... and not one I would have thought of.

Mac OS X only needs 5 fonts in its System/Library:

Monaco.dfont
LucidaGrande.dfont
LastResort.dfont
Geneva.dfont
Keyboard.dfont

... unless you want to run Limewire in which case it appears you need Helvetica. Once I made this active, Limewire loaded fine.

If you're still having problems, try it!

Vic