It's not a case of having a lot of fonts. It's more a case of having the right fonts for Firefox. You can have lots of fonts installed, but none of them might be used by Firefox - and hence the problem.
This is what I'm currently running on my Fedora 8 system in terms of fonts. I also had font problems until I installed a few packages:
CODE
[ian@esprit ~]$ rpm -qa | grep -i ttf
baekmuk-ttf-fonts-common-2.2-6.fc8
baekmuk-ttf-fonts-gulim-2.2-6.fc8
[ian@esprit ~]$ rpm -qa | grep -i font | grep -vi ttf
fontconfig-2.4.2-5.fc8
fontconfig-2.4.2-5.fc8
paktype-fonts-2.0-2.fc8
jomolhari-fonts-0.003-4.fc8
xorg-x11-fonts-ISO8859-1-100dpi-7.2-3.fc8
tetex-fonts-3.0-44.3.fc8
terminus-font-console-4.20-8.fc8
bitmap-fonts-0.3-5.1.2.fc7
lohit-fonts-malayalam-2.1.5-3.fc8
lohit-fonts-telugu-2.1.5-3.fc8
libXfontcache-1.0.4-3.fc8
dejavu-lgc-fonts-2.19-1
sazanami-fonts-gothic-0.20040629-4.20061016.fc8
lohit-fonts-tamil-2.1.5-3.fc8
lklug-fonts-0.2.2-5.fc8
lohit-fonts-punjabi-2.1.5-3.fc8
dejavu-fonts-2.20-1.fc8
chkfontpath-1.10.1-2.fc8
urw-fonts-2.4-3.fc8
xorg-x11-fonts-misc-7.2-3.fc8
xorg-x11-fonts-truetype-7.2-3.fc8
lohit-fonts-bengali-2.1.5-3.fc8
lohit-fonts-hindi-2.1.5-3.fc8
lohit-fonts-gujarati-2.1.5-3.fc8
kacst-fonts-1.6.2-2.fc8
xorg-x11-font-utils-7.2-2.fc8
ghostscript-fonts-5.50-18.fc8
bitstream-vera-fonts-1.10-8
msttcorefonts-1.3-4
xorg-x11-fonts-100dpi-7.2-3.fc8
cjkunifonts-uming-0.1.20060928-4.fc8
lohit-fonts-kannada-2.1.5-3.fc8
mplayer-fonts-1.1-3.fc
libXfont-1.3.1-2.fc8
liberation-fonts-1.0-1.fc8
libfontenc-1.0.4-4.fc8
lohit-fonts-oriya-2.1.5-3.fc8
xorg-x11-fonts-Type1-7.2-3.fc8
terminus-font-x11-4.20-8.fc8
package names might change, but here is an idea of what additional packages I installed:
http://gentoo-wiki.com/HOWTO_Xorg_and_Fontslook in the emerging the necessary fonts section, I installed most of these:
QUOTE
These are the necessary packages:
* x11-base/xorg-x11
* media-libs/freetype
* media-fonts/corefonts
* media-fonts/freefonts
However I advise you to also install these useful fonts (note: media-fonts/unifont blocks dev-util/eclipse-sdk):
* media-fonts/ttf-bitstream-vera
* media-fonts/artwiz-aleczapka-en
* media-fonts/sharefonts
* media-fonts/terminus-font
* media-fonts/unifont
* media-fonts/dejavu
* media-fonts/liberation-fonts-ttf — "A GPL-2 Helvetica/Times/Courier replacement TrueType font set, courtesy of Red Hat".
the package names can be more or less the same. Firefox was crap before I installed these packages. Hope it helps a little, it should at least help you with the fonts in Firefox if you don't have some of these already.