Firefox 0.9.3 / GNOME 2.6.2 problems

I have found several problems with Firefox 0.9.3 on a fresh Slackware 
10.0 installation with GNOME 2.6.2.

1) All menus items are completely white when selected.  You can't read 
the text of the currently selected menu item because it is completely 
white.  The same with top level menus.  This problem exists with 
Thunderbird 0.7.3 also.

2) In Edit->Preferences pressing "OK" does nothing.  I can't set any of 
the options.  Great.  Cancel works though.

3) Selecting the "Add Engines" menu at the top right corner (to download 
the Google Groups Engine) does nothing.

I would like to add that I have run this same version of Firefox 0.9.3 
on both Windows XP and Slackware 10 (with KDE...it was a previous 
installation of Slackware) without encountering these problems.  I 
installed the programs as a regular user in the /home/_username_ 
directory.  If anyone knows how to fix any of these problems I would 
love to hear from you.