Scrolling bug in Firefox 5

I'm using Firefox 5.0 on Windows XP. When I try to scroll using the scroll wheel or scroll bar, it tries to scroll, but then the scrolling position snaps back to where the caret (text cursor) is. The only way I can scroll is by moving the caret, which is a bit annoying when working with a large manuscript (imagine doing this with an 80,000-word novel), though at least the page up/down keys can speed up the process. The problem doesn't always manifest immediately upon launching Writer, but rather it seems to randomly appear and go away.

So far I haven't gotten this problem in Chrome 12, but I haven't tried it much, and Firefox 5 is my main browser anyway.