Font problems in Firefox,Thunderbird

I have openSuse11 on my Compaq6720s (widescreen) and I am experiencing several problems with GTK applications.
Firefox, Thunderbird, Pidgin and some other runs, but they draw no text (windows are blank).
All my attempts to fix it by changing fonts in yast failed.
I will appreciate any advice.

First try re-naming the hidden .mozilla or .thunderbird folder to eg; .mozilla_old

When you try FF what happens. If it’s the same you can delete the new one and rename the old back in.

In the Main Desktop Config, go to the fonts section and set it back to defaults. See what happens.

It works now, Thanks very much (after renaming .mozzila).
It is much easier with firefox now:).
Thanks once again.