Kernel Panic? (the dimmed screen, with the multi-lingual, and restart)
Which version OS-X are you on?
Without looking at the Safari crash log, and/or others, it'd be just a wild guess as to cause. It's something pretty seriously corrupted, or worse a hardware problem (RAM?).
It's worth doing "Safari->Empty Cache..." and see if it helps.
Otherwise, verify disk (Disk Utility - First Aid). If the verify fails, reboot on your restore CD (or OS-X install) and run Disk Utility from there to perform the repair. Once you have the disk verified, do a repair permissions.
If that doesn't help, next I'd re-install the latest OS-X update, using the OS-X combo updater for the version you are running (like 10.4.8, hopefully).
Hope one of these more generic techniques help.