Before you put Firefox 3 beta 5 in production, please take note of the beta-ness and be aware of this very serious show-stopping bug that still needs resolution:
https://bugzilla.mozilla.org/show_bug.cg
http://bugzilla.kernel.org/show_bug.cgi?i
Two months in to accumulating browser history, Firefox 3 is now completely unusable for me. Also note that this fsync behavior means that FF3 profiles cannot be stored on NFS-mounted home directories.

Comments
I'm changing distro's just for this. Sick of the bugs and the way we are asking for them.