firefox interface fonts & gnome-control-center

I am looking for help eliminating an annoying interaction between firefox and the gnome control center. I startx, using openbox, and invoke firefox. The interface fonts (menu, etc) are huge. I invoke gnome-control-center, click "fonts", and immediately the firefox (and gnome-control-center) fonts all shrink to right size. I exit gnome-control-center only to find it has redefined my keys so I have to rerun xmodmap. This is all just annoying, and I would like to understand enough to get rid of it. I tried to purge my system of all things gnome but core SuSE utilities need enough gnome and gtk libraries that I couldn't do it. Thanks, Henry Harpending