Man, at this point I think the only option you have for further troubleshooting is to wipe your main hdd, reinstall windows along with dx9.0c, video drivers, and wow.
You could try troubleshooting those various AGP settings in your bios first. Since it is graphics related, but you have switched cards and drivers, these would be the only variable left. I can't say much about them offhand, but I'm sure if you search for Fast Writes, Aperture, Shadowing etc you will get more detailed info.
Oh one more avenue. Do you overclock? Make sure your AGP/PCI slots are locked at 66/33mhz within the bios. Also if you are running SATA hdd's I believe 2 of the SATA ports on this motherboard are susceptible to erratic errors because they don't have a speed lock on them to separate from the bus - but I could be thinking of another mobo.
You could try troubleshooting those various AGP settings in your bios first. Since it is graphics related, but you have switched cards and drivers, these would be the only variable left. I can't say much about them offhand, but I'm sure if you search for Fast Writes, Aperture, Shadowing etc you will get more detailed info.
Oh one more avenue. Do you overclock? Make sure your AGP/PCI slots are locked at 66/33mhz within the bios. Also if you are running SATA hdd's I believe 2 of the SATA ports on this motherboard are susceptible to erratic errors because they don't have a speed lock on them to separate from the bus - but I could be thinking of another mobo.