I have no knowledge about the installation of Gimp when it comes to OX Leopard System (because mine is Windows xp). Though I think that it may be because of compatibility issues to the OS or the size Gimp loads may be the reasons of crashing. Is the installer "Mac OS X" or "Gimp on Mac"? And also look if it is a "stable version" or "unstable version". Hope you can find a way. Ask and try more=)
Get involved! (see UI Brainstorm!). Discuss or seek help from other Gimp users and developers. Be part of the Gimp mailing lists to create and receive daily topics. Gimp Users and Gimp Developer are good to try.
NO!! Don't delete the fonts, put them back if you still have them NOW!! BoxeD was joking since he deleted fonts and Gimp didn't work. From the error it sounds like X11 isn't up to date. Or maybe XQuartz is out of date. http://xquartz.macosforge.org/trac/wiki
Now I have a real problem with the fonts. I deleted them and the computer is behaving strangely. You guys really shouldn't joke with a newbie! We can't tell if you are joking. How do I reinstall fonts? Now what do I do? I restarted the computer and the weirdness hasn't continued but my documents are all coming up in different fonts.