Demetri and others,
The subject of the pronunciation of Attic Greek is very interesting. Until the 1400's, Attic and Koine were pronounced in the modern fashion (which has not really changed since Byzantine times). So we have for instance "o keereeos" not "ho kurios" for example for those who do not know what I am talking about.
Erasmus came up with his "Erasmian" pronuncation to try and make Homer actually rhyme like it should of. He was partially correct.
Modern scholars in the western world went further and actually reconstructed Attic Greek with its pitch accents (instead of stress--think Chinese tones!). Also, f is really an aspirated ph, x is really an aspirated kh, and th is really an aspirated t(h), which pair to their unaspirated counterparts of regular p, k, and t. For English speakers we have both varieties but we do not distinguish them for meaning, rather it only varies where the consonant is in a word (think stop versus put in English; pronounce each out loud and notice the difference in the p).
In Greece they choose to teach with the Modern pronunciation even though they are aware of the reconstructed pronunciation. According to "right and wrong" this would be "wrong" but the reconstruction is only a theory anyway and besides, modern Greek and classic share a large common vocabulary so what would be the point for modern Greek non-specialists to have to relearn the pronunciation? It would cause more harm than good.
If you look at seminary textbooks, they used to all be "Erasmian" but now they are showing both Erasmian and Modern. At SVS we learn the Modern pronuncation since this is used in the liturgy. I think it helps to know the reconstructed pronunciation too (I could pull it off if I had to), but I think Modern pronuncation is more beautiful.