Complete lockup when idle

For me, a new and odd problem. If I turn comp on, then make a coffee while booting, 5 mins later it is usually locked up tight. No Cont-Alt-Del, no mouse.. glued tight. I must Reset or power off, then it wants to chkdsk D: drive upon reboot.
D: is marked 'dirty'; chkdsk never finds a problem, so i disabled it by with chkntfs d: /x

Lockup doesn't seem to happen if I start work right away, but does sometimes if I play Spider Sol. whilst downloading!

This all since last official updates to XP OS, maybe coincidence? I cleaned fan, suspecting heat prob.. reseated memory chips. 640 megs memory, new 1 gig AMD, new Abit mom brd. hmmm? At a loss

Lyman

 

Have you tried a chkdsk /r to get an exaustive check of the drive? It takes a bit longer but will find errors that may otherwise have been missed.