Fixing Mathematica 5.0 on Ubuntu Edgy (and maybe Dapper or other distros).
It seems that Mathematica needs /usr/X11R6/lib/X11/locale, while recent Xorg servers have apparently moved locale data to /usr/share/X11/locale.
SYMPTOMS: Mathematica starts up, shows the splash screen for a while, and then crashes.
SOLUTION: Create a symlink to /usr/share/X11/locale from /usr/X11R6/lib/X11:
sudo ln -s /usr/share/X11/locale /usr/X11R6/lib/X11
HTH. HAND.