From a post I made 2 1/2 years ago...
Nicholas was kind enough to provide some information, so I suppose the best place to start is with the information/points which have already been provided:
In 1968 the State Church of Greece added Augustine's name to the Church Calendar. Other Churches followed that example.
While Augustine's name might have been added in 1968 to the Calendars used by some Churches, he had long been considered a saint, as a careful review of the contemporary and ancient teachers of our Church demonstrate. Since the facts provided to us by Nicholas proceed in a (more or less) reverse chronological order, it would perhaps be best to likewise go backwards in time as we consider the available information. So, let's start in the 20th century and start working our way backwards.
According to Fr. Seraphim Rose, "in the official calendar of one of the 'Old-Calendarist
' Greek Churches," Augustine is called "'Saint
Augustine the Great" (Emphasis mine).  Many (though not all) within the contemporary Russian Church also viewed Augustine as a Saint. As an example, it is said of Saint John of Shanghai and San Francisco:
"Archbishop John Maximovitch, when he became ruling bishop of Western Europe, made it a point of showing special reverence for him (together with many other Western Saints); thus, he commissioned the writing of a special church service in his honor (which until then had not existed in the Slavonic Menaion), and this service was officially approved by the Synod of Bishops of the Russian Church outside of Russia under the presidency of Metropolitan Anastassy. Archbishop John celebrated this service every year, wherever he might happen to be, on the feast day of Blessed Augustine." 
Besides Saint John, and Fr. Seraphim Rose (who wrote an entire book in defense of Augustine), most (if not all) of the other prominent writers in Orthodoxy also seem to have considered Augustine a Saint. Here's some examples: Archbishop Averky (whom some consider a Saint) calls Augustine "Blessed" in his Commentary on the book of Revelation
; Fr. Michael Pomazansky calls Augustine "Blessed" eighteen times in his work Orthodox Dogmatic Theology
, and quotes Augustine as an authority about a dozen times in this text ; and Fr. Georges Florovsky also acknowledged that Augustine was a Saint in his work Bible, Church, Tradition
(and probably others). I have no doubts that if I had more books by 20th century theologians, I would find more evidence.
That Augustine was considered a Saint can also be seen in the hagiographical material of the 20th century. The Prologue From Ochrid
, for example, which was compiled by Saint Nikolai of Serbia, lists Augustine as a Saint of the Church (June 15th). The admittedly short entry from the Prologue
on Augustine says:
"He was turned from paganism to Christianity through the advice, tears, and prayers of his mother, Monica. He was a great Doctor of the Church and an influential writer, but with certain unacceptable extremes in his teaching. He served and glorified the Lord for thirty-five years as Bishop of Hippo and lived seventy-six years on earth in all, from 354-430."  [A note--the Prologue also has short entries on other great luminaries of our Church, such as Bl. Theophylact of Bulgaria]
As we go backwards in time we find other examples of Augustine being considered a Saint. For example, while the State Church of Greece may not have added Augustine to their Calendar until 1968 (I'm assuming that that is a fact, though I've not attempted to verify it), the Russian Church had added Augustine back in the 19th century. And of course, adding
someone to a calendar is not an acknowledgement that, up until the addition, a Church had not considered someone to be a Saint. Many western Saints were only added to Orthodox calendars within the past few centuries.
The next piece of information Nicholas provided for us was the following:
Nicodemus of the Holy Mountain (1749-1809) was given selected writings of Augustine by Uniate visitors. Impressed with the extracts, Nicodemus placed Augustine's name in the Greek Synaxaristes (June 15th) with a troparion by Michael Kritoboulos.
Nobody is infallible, so I wouldn't automatically dismiss the possibility of Saint Nicodemus being tricked. However, I think it should be remembered that Saint Nicodemus was far from ignorant of the writings of the Church Fathers, and the divinely-inspired contents of the Ecumenical and Local Councils. Isn't it probable that the words the holy Fathers used about Augustine had some part to play in the decision of Saint Nicodemus to include Augustine in the Calendar? Saints Mark of Ephesus (15th century)  and Photius the Great (9th century)  considered Augustine a Saint--perhaps Saint Nicodemus simply reaffirmed what these two great saints had believed?
And these two Saints were not alone. A western example of how Augustine was perceived can be seen in the writings of Saint Bede the Venerable (7th century). A prominent example of Bede's respect for Augustine can be found in his commentary on the First Epistle of John. In his commentary, the Venerable Bede quotes the Church Fathers a total of sixty-one times, with fifty-three(!)
of these quotes being from Augustine's works. (What's more, Bede alludes to, but does not directly quote, Augustine three additional times in his commentary on 1 John).  Saint Bede was one of the more learned and well-read men in the west at that time, and had obviously read Augustine extensively. It's doubtful that this saint of the Church simply didn't see what some today consider blatant heresy. It's much more likely that Saint Bede just didn't consider Augustine's errors as extreme in nature as some Orthodox do today.
Which brings up a question: which Saints
did consider Augustine a heretic? That seems like it'd be a good aspect of this debate to explore. So far as I can see, as we read the other writings of the Saints through the centuries, we see the following consistent pattern: an acknowledgment that Augustine made some errors, and even that some heresies sprung from certain sayings of his, yet a simultaneous and equally forceful acknowledgement that Augustine is in fact a Saint in the Church, and can be quoted as an Authority. But perhaps there are saints that I am not aware of who held a contrary view? If there are, we can discuss that in future posts, but for now I'll move on to the Ecumenical Councils, which also speak of Augustine as a Saint.
Fr. Seraphim Rose mentions in his book on Augustine that the 7th Ecumenical Council praised him (and apparently recognized that he was a saint).  Blessed Augustine was also mentioned favorably in The Letter of Pope Agatho to the Emperor and the 6th Ecumenical Council.  And during the first session of the 5th Ecumenical Council, Saint Justinian mentions Augustine in the midst of some of the brightest divine lights in the Church's history, making no distinction between the place of Augustine and the other saints mentioned:
"We further declare that we hold fast to the decrees of the four Councils, and in every way follow the holy Fathers, Athanasius, Hilary, Basil, Gregory the Theologian, Gregory of Nyssa, Ambrose, Theophilus, John (Chrysostom) of Constantinople, Cyril, Augustine, Proclus, Leo and their writings on the true faith." 
To help give a bit of context for this quote, I'd like to quote something else that Saint (Emperor) Justinian said:
"...we want you to know that after the definition of the holy Synod of Chalcedon had been drawn up, Theodoret too, in that he had written against the Twelve Chapters of St Cyril and had defended the wicked teachings of Nestorius, was ordered to anathematize Nestorius and his impiety and to confess that the holy, glorious, and ever-Virgin Mary was Theotokos before he was received. For this reason, then, neither Ibas nor Theodoret are considered teachers and Fathers, but as men who repented and anathematized those wicked teachings that were the cause of their being accused. When they received the definition of the Synod of Chalcedon and subscribed to it they were received, since it is the custom in the catholic Church that when heretics have left all their error and have returned to the orthodox faith they are received into communion, but they are not reckoned by the fathers as teachers ...We want you to know this as well: not only were Ibas and Theodoret exprelled from the episcopate because they spoke against the Twelve Chapters of St Cyril, but Domnus, Archbishop of Antioch, was censured simply because he had written that one ought to keep silent concerning Cyril's Twelve Chapters." (emphasis mine) 
One might also consider Saint Justinian's views on Origen. Clearly, then, Saint Justinian was against
counting heretics who had repented of their heresy as teachers or Fathers of the Church. And obviously he would be even more
strict with those who were unrepentant
(or defended the errors of those who were heretics). I believe we can safely assume (based on the evidence) that Justinian knew that Augustine had made some errors, and indeed that Augustine had "retracted some of his own writings, and corrected some of his own sayings," as the Pope of Rome put it in his Epistle that Confirmed the 5th Ecumenical Council. 
Yet, in spite of Augustine's errors, and in spite of his seemingly strict understanding of the doctrinal purity required to be an authoritative teacher, Saint Justinian doesn't hesitate to identify Augustine as a Saint of the Church, both at the Fifth Ecumenical Council and in other texts he wrote.  Certainly Augustine had errors--but apparently they weren't severe enough to make Augustine unsuitable to quote as an authority.
We should also note at this point what Nicholas himself told us: that the 4th Ecumenical Council considered Augustine a Holy Father. Whether the Ecumenical Councils under Saints Photius and Palamas mentioned Augustine I don't know, though I don't consider it unlikely. Before we go on to the rest of the information that Nicholas provided, let's sum up what has been said thus far:
- Many prominent and saintly Orthodox thinkers in the past few centuries considered Augustine a Saint.
- Many of the Saints of the Church considered Augustine a Saint, and considered him an authority.
- Augustine was mentioned at the 4th, 5th, 6th, and 7th Ecumenical Councils--always favorably.
This summation brings us up to the mid-5th century. The next piece of information that Nicholas provided for us brings us to the early part of the 5th century:
In 415, Palestinian bishops of the synods of Jerusalem and Diospolis disapproved of his views.
It is my understanding that the Palestinian bishops were lied to by those very people whom Augustine was writing against. If this is so then Augustine obviously wouldn't be discussed in an even-handed manner. What I'd like to know is, was Augustine condemned at any Council that was deemed Orthodox (e.g., was he condemned at a Local Council that was later confirmed by an Ecumenical Council)? Even if such a condemnation at a Council actually existed, it wouldn't prove that Augustine was a heretic,  but it would be evidence I'd be interested in seeing.
If my understanding of the Council mentioned above is correct, then using this Council to demonstrate that Augustine was a heretic would be like using some of Saint Gregory the Theologian's words to demonstrate the Orthodoxy of Maximus the Cynic (who was planted to sway Gregory towards agreeing with the Alexandrian positions, and who eventually--when Gregory couldn't be swayed--betrayed Gregory and was part of his eventual downfall as Patriarch of Constantinople). In other words, sometimes people are wrong and mistakenly praise of condemn someone based on false knowledge: we certainly wouldn't want to take their mistakes and use them to inform our understanding of who is and isn't Orthodox.
(As a clarification of my last point, I'd note that while saints or councils can err, when the mind of the Church accepts something and it becomes obvious what the Orthodox position is, we see less and less possibility of something being misunderstood or false. I'm speaking here, of course, of those types of things which weren't handed down from the Apostles, those traditions we are of course fully sure of. So, while I don't think there's a problem believing that a Father here or a Council there misunderstood Augustine, I think there is a problem in claiming that Augustine was really a heretic and was misunderstood by almost every saint and council for century upon century)
Many people did react to Augustine's exaggerated doctrines, of course; but the question I have is: how many Church Fathers who knew all the [relevant][ facts
, and had read Augustine's works, actually condemned him? When Saints such as John Cassian and Vincent of Lerins spoke against the doctrines Augustine promulgated, for example, they didn't openly attacked him, but focused on the erroneus beliefs while passing over the source of the beliefs. They didn't come anywhere near condemning Augustine in their writings. Again, we return to the issue that I brought up before regarding which saints, if any, condemned Augustine as a heretic.
Well, I guess we are now at the last piece of information that Nicholas provided:
The Fourth Ecumenical council lists him as a holy Father of the Third Ecumenical Council. This is incorrect as he died 10 months before the 3rd Ecumenical Council!
On this point I'm not sure what to say. For the sake of discussion, I'll proceed and assume that the claim is true. My general response to this is to ask a question: Why is this thought to be a persuasive argument against Augustine?
I guess I don't quite get it. The point of the argument seems to be that the Council got the date wrong, and so we should not trust the Council's entire view of Augustine. I don't believe that such an all-or-nothing argument is in keeping with the spirit of Orthodoxy, however.
It seems to me that having exact dates was not always a major concern for the Church. For example, was the 2nd Ecumenical Council a Council of 381 only, or both 381 and 382; and if both, why do we usually say it was in 381? We could ask such a question about many events. Or, to look at it another way, consider that we normally speak of the Creed in somewhat incorrect terminology. There were additions to the Creed at the 2nd Ecumenical Council, but how many of us talk about the "Nicene-Constantinopilitan Creed"? Don't we almost always simply call it the Nicene Creed? These are unimportant inaccuracies (or seeming inaccuracies), what is vital is the basic content of the subjects being discussed.
Maybe it's hard for we in the west to understand this approach, since we grew up being taught that accuracy in such matters was of supreme importance (if you wished to be considered a "good scholar"). The Fathers had no problem giving incorrect dates, the Fathers forgot what the names of the first Popes of Rome were and what order they succeeded each other, to put in in a word, the Fathers just didn't seem to be worried about the same types of things that we are. But I guess that's a warning that we need to conform ourselves better to the Church and her teachings and mind and spirit.
Maybe the thd Ecumenical Council meant to speak of Augustine (as relating to the 3rd Ecumenical Council) as being a part of it in the same way that Saint Peter the Apostle was proclaimed as having been a part of the 4th Ecumenical Council. Or, maybe the 4th Ecumenical Council made a mistake. I don't know, I've not seen exactly what the 3rd Council said of Augustine. What I do know is that the majority of Church Fathers, and the Ecumenical Councils, accept Augustine as a Saint. So be it. So be it.
 Fr. Seraphim Rose, The Place of Blessed Augustine in the Orthodox Church, (Saint Herman of Alaska Brotherhood, 1996), p. 79
 Ibid., p. 79
 Archbishop Averky, The Apocalypse: In the Teachings of Ancient Christianity, (Saint Herman of Alaska Brotherhood, 1998), p. 258
 Fr. Michael Pomazansky, Orthodox Dogmatic Theology, (Saint Herman of Alaska Brotherhood, 1997)
 Saint Nikolai (Velimirovic), The Prologue From Ochrid, (Lazarica Press, 1986), Volume 2, p. 318
 Rose, Augustine, p. 66
 Ibid., p. 70
 Dom David Hurst, Commentary On the Seven Catholic Epistles, [Cistercian Publications, 1985]
 Rose, Augustine, p. 116
 Pope Agatho, Letter to the Emperor And The 6th Ecumenical Council
 Saint Justinian, Emperor's Letter From the 5th Ecumenical Council
 Saint Justinian, A Letter On The Three Chapters (Kenneth P. Wesche, On the Person of Christ: The Christology of Emperor Justinian, [Saint Vladimir's Seminary Press, 1991], pp. 152-153)
 Pope Vigilius, Decretal Letter
 cf Wesche, Christology, pp. 155-156, 196
 I say that it wouldn't prove that Augustine was a heretic because there are precedents in Church history where 1) a Saint, and 2) a Council who condemned that Saint, were both accepted. For example, one of the Local councils whose canons were accepted into Orthodoxy actually confirmed the condemnation of Saint Athanasius. In other words, we ignored the condemnation of Saint Athanasius, but accepted the canons. I don't recall which council this was off the top of my head, but I can get more information if anyone doubts that it's true.