I too am having problems with an ASUS K7V and an AMD CPU (800MHz). I've swapped out the motherboard to no avail. I've tested the computational characteristics of the CPU using a tool called "The Troubleshooter" and it appears to be fine. The problem I'm having is it locks up after a 3D engine is initialized. I've tried the only video cards I have available to me, a Diamond Viper 550, and a Viper 770. Both cards perform fine in several other systems. I'm running Windows 98SE and 128MBs of PC133 SDRAM.
ASUS support is a nightmare! If you can get them to even respond! I bought the CPU at a trade show and AMD doesn't even warranty it!
Anyone able to solve this one?