|ATI Rage Fury Pro Gl lock

I am running an ATI 128 Rage Fury Pro AGP on a Asus PL297 MB. PII 233 - 98mg
I play Heretic2 and I have been able to get the openGL32 to run,some…
BUT, it crashes every little while, from 1 min to 30 min playing time before the card locks up, the sound loops, and normally requires a system restart.
I’ve installed the drivers and upgraded to the beta ATI drivers for that card too. I’ve also installed the Win98 missing default drivers(vflatd.vxd and vdd.vxd).
But I still lock and crash
Any ideas?