System is a Celery 300a O/C'd to 464mhz @ 2.2v (VERY stable, I just ran WB98 Cpumark32 all night in demo mode, no crashes).

My CL TNT is NOT overclocked in any manner (memory or processor).

It will do the Final Reality bench fine, as long as I only do one or two passes. If I go into "advanced" mode and run it (it does 5 loops of each benchmark then), it will "lockup" the video card either in the robot scene, or sometimes a bit later (last scene).

Now I know it ain't the case cooling, because I'm using a 100CFM fan to push air though the case (its blowing directly onto the CL TNT, from the front of the case), and the ambiant case temp near the empty fan grill in the rear is only a degree or two above ambiant room temp (most air exits through that grill).

Think that I need to put a bigger heatsink on the CL TNT? Get rid of that dammed thermal tape and use heatsink compound (dunno how I'd attach it to the chip though). Maybe get another heatsink to put on the other side of that board?

Anyone else have this problem? Is this a "defective" board, or the norm?