Comment 13 for bug 444449

The same happens on my 9.10 (i386, nvidia gpu with release 185 of drivers, compiz enabled).
But I don't think this is exclusively caused by firefox, because:
a) firefox 3.5 scrolling was as fast as 3.0 when I ran it on jaunty
b) chromium scrolling was fast in jaunty, and is now much slower after upgrade to 9.10 (but not as slow as firefox 3.5).

Moreover I noticed that "arora", a qt-based browser, scrolls very fast on 9.10, as fast as chromium was on jaunty (and is not anymore on karmic). Since they are both built on webkit, the difference seems to be in GTK vs. QT.

Maybe the problem is cause byt the combination of new GTK + firefox 3.5.