Address error... HD corruption?
Run Disk First Aid and see what it comes up with...
With an overclocked G3 card, USB card, ATA card, VooDoo 3 its no wonder there are problems...
Peripherals never seem to play nice with each other.
Remove each one and its drivers, try UT, then put one back on the chain, try again, and see if its a certain peripheral...
Oh yeah, make sure you have the latest drivers for all those devices...
Cipher13