You might check to see if the text in the expanded window just isn't being displayed, or if it isn't being posted either. I believe I've seen the situation where the text box didn't open, text was entered into the expanded text box but didn't appear in the main window, but nonetheless was posted successfully.
BTW, the problem for us has been very inconsistent. We haven't had any reports of problems for a month or so, even though there hasn't been any changes in our lab computers. And, to make things even more confusing, the same people on the same computers would have the problem, then not have it, then have it again, with no identifiable reason.
Does anyone have an idea why the problem would be intermittent? That's the one that puzzles me the most.
Most people never experienced the problem. We have around 500 users in the db, with maybe 200 pretty active. Generally we are very happy with Moodle.
Mick