Some workarounds and fixes for annoyances I've recently encountered in Fedora:
Fedora Planet display problems in Firefox 2 (F8) and 3 (F9) -- this is caused by Mozilla bug 215055 which is due in part to a nasty X issue. Turning off smooth scrolling helps considerably (but doesn't solve the problem) ... Edit > Preferences > Advanced > General Tab > [Uncheck] Use smooth scrolling
Unable to boot from a CD using KVM -- this is caused by bug 452355 and rectified by libvirt-0.4.4.-2, apparently on its way to updates. I encountered this while trying to update a web-facing VM from fc6 to f9 so that I could install the critical DNS updates (DO NOT skip these updates, which have been released for F8 and F9).