It doesn't seem to be a very widespread problem (if indeed spread at all ). What extensions are you using? What version of Firefox?

Why not try different versions of Firefox - I'm actually using the beta of Firefox3 and I think it's great. <a href="http://www.mozilla.com/en-US/firefox/3.0b2/releasenotes/">Link</a>.

You could also try disabling your extensions one by one to see if the problem stops.