I’ve been suffering from a problem in FireFox 3 and was about to assume it was my system playing up when I caught this post from Rick Strahl.
It seems that the Caching in FF3 is indeed a little too aggressive. I’ve also noticed that as a user of the Web Developer toolbar add-on for FF using the Clear cache feature on that is no good. You have to use the clear private data dialog to force tha cache to dump its contents and give you a chance to re-load.
I haven’t had time yet to see if this has been reported to Mozilla I hope it has because this is a real pain.
Rick puts a lot of detail down in his post so it’s worth reading through if you have been suffering from cache issues since installing FF3.