This post on a previous thread from someone else expresses the same problem - but what is the answer?
From the response page, I start typing my response, but when my response gets beyond the limits of the viewport (that ~1" x 5" input screen), the text keeps jumping up and down. What I mean is that the viewport isn't synchronizing with my typing. The cursor remains where I am typing, but the view keeps jumping back to the point where the text limit was reached for the viewport.
I've gotten in the habit of using a separate text editor and then just cutting and pasting, but it is so time-consuming to type in formatting tags.
I participate in several forums on the I-net, and this is the only one that has this problem (for me, anyway), so I suspect it's not my browser.