Odd permissions problem with Pango and Firefox
I've got Slackware 10.2 installed, but I've built from source and installed pango-1.12.3, gtk+-2.10.0, glib-2.12.0, cairo-1.20, glibmm-2.8.9, gtkhtml-3.0.10, gtkmm-2.4.11, libiconv-1.9.2, libpng-1.2.12, and libsigc++2.0.17. I have built the CVS source of firefox, and when I run it through sudo (sudo $PATHTOFIREFOX/firefox) it renders everything perfectly. If I don't use sudo, on certain sites that render perfectly under sudo I get, e.g.:
Pango-WARNING **: Cannot open font file for font Helvetica 10.7685546875
as well as other sizes and fonts, depending on the site. Such affected fonts are blank onscreen.
Interestingly, when I go to print as a regular user, it prints from Firefox fine, but I can't print using sudo!
Anybody have any idea what's going on? I have removed all other versions of the installed-from-source files above.
By the bye, I've also built and installed the CVS version of emacs, and it runs just fine, so I think all dependencies are happy.
Of course, I'd be grateful for any help or insights or even wild guesses.