Interesting problem after changing CPU... Ideas?

[alembic5]

I purchased a Tbred 2600 from a fellow anandtech member. I put it into my A7V8X deluxe (which has been running my XP1700 for over a year with no problems...) and flicked it on. It made it through post, started booting into windows, and then... my hard disk powered down! It then powered back on. And back off again. (you get the idea.) I put my 1700 back in, and the problem remains! I have an antec tru-power 480 watt psu, but the voltages seem a little low to me. Have any of you had this problem before? I haven't yet tried swapping the psu's, but I will be trying that tonight. I also tried swapping out some different hard disks, and they did the same thing. (both SCSI and SATA.) Any ideas on what would cause this to happen?

 

[LemonHerbWRX]

Check for a BIOS update? Try jumping the BIOS and putting one of the processors back in after that.

 

[alembic5]

The bios is up to date... and the chipset obviously supports the processor. This is the first time I've ever had this problem...