ibook firefox clashing

Why

1. is Firefox crashing at random times
2. will it not restart when I try to relaunch it? I get the little zoom effect from the icon, but then nothing... it never appears in the dock. I have to reboot the ibook to get Firefox to launch again.

BTW, after booting in safe mode and running this somewhat obscene sounding Unix command, I don't seem to be getting kernel panics on nearly as regular a basis as before.