Just tested on IE8. Problems still there.
Now that I have IE8 to test, below is a more accurate description of the unexpected behaviour.
1. In each onkeypress event, the text scrolls up until the cursor is at the bottom line of the textarea (while still at the same position of the text)
2. Scroll down to the bottom of the text (with the focus not in textarea). In each onfocus and onblur event of the textarea, the text will scroll up a page or two automatically before inserting the cursor (for onfocus only) at the intended position which by this time is already not at the position you want.
Hey Hien, I tested earlier today and noticed it was still there too. And I managed to find some other people experiencing the same thing. It turns out to be a pretty common IE8 bug. You can see the same behaviour on Wikipedia editing pages in fact
The problem is related to the width being set in percentage values on the textarea. We use something like "width:98%" to make sure it is always nice and big. But IE8 apparently doesn't much like that. We'll have to put in a hack to specify the width something like this: "width:520px;min-width:98%". And that fixes it. Ugly, but true. Hopefully it doesn't break other browsers! IE6 wouldn't pay attention to that min-width I'm pretty sure.
Anyway, I just need to make sure my code is up to date and I'll upload a fix.
By the way, this problem exists in the forum and blog entry forms as well. And I guess also the wiki form, though I didn't test there myself.