When I open the about dialog in Firefox the Help menu name stays white when it should return to black. This is the case with any modal dialog opened from a menu (the other example I can think of is Save As). I originally filed this bug directly with Mozilla (https://bugzilla.mozilla.org/show_bug.cgi?id=316780) but it seems to have been caused by one of the patches that Gentoo applies to Firefox. I compile my Firefox from CVS with an ebuild I made myself and I thought it was a Firefox bug. It appears though that it's only for Gentoo users and it happens with the 1.5-r4 ebuild as well. The problem went away when I stopped using some of the Gentoo patches in my ebuild but I'm not sure exactly which one. This behavior is not found in the nightly builds from Mozilla and I have not tried the mozilla-firefox-bin ebuild. Mozilla's bug 316780 has a screenshot that might make what I'm talking about clearer.
I am unable to dupicate with -r4 or -r9. Have you tested profile as I have stated in the ebuild? If not I think you should start looking at plugins you might have installed.
My little brother just installed Gentoo for the first time in his life yesterday. He had no existing profile and Gnome had just finished emerging when I asked him to check. He doesn't even know enough about portage to find any plugins yet. He's on amd64 (as am I) and I've also confirmed it with a friend using an x86 laptop.
it is a known issue with default theme in gnome for problems most have resolved by changing there gtk theme.
Closing, Anarchy makes a compelling argument.