I guess you'll have to tackle this by the scientific process of elimination.
Hardware - Make sure all cards and cables are properly seated, inside case and out.
Oh yeah, maybe your RAM is bad?
Software - the OS. A backup and re-install is the most obvious, but not after checking what apps you might be using when it locks up.
For this to happen on a new G5 is unacceptable, since my girlfriends iMac has been running 4 years with hardly a glitch.
[ June 09, 2004: Message edited by: cocoamix ]