Do I read that right: this happens under all OS's? Are you dual booting? Used to have similar problems running W2K and RedHat6.something. Uninstalled everything and went for removable drives in caddies. One OS per drive.

Have you tried

• swapping boards around in the slots
• fitting another graphics card
• flash upgrading the graphics card BIOS (or whatever)
• flash upgrading the MOBO BIOS or
• using MOBO BIOS safe or fail-safe setting?

If your MOBO has a setting called something like "AGP 4X Mode" disable it. I know it sounds screwy but it worked for a problem I had with an 8X card on an Asus dual PII board.

An outside possibility is a dry solder or broken solder somewhere on the board. In which case it's a trip to your local PC dealer. Hope you get it all sorted soon.

Cheers,
Mark