problem with pci-e slot

[SPEEDemon1]

I just purchased a second msi 8800gt card for my computer. I put the second card in, attached the sli bridge, and noticed that my first card was now running at half its speed, and my 3dmark06 score went down by about 500, which obviously shouldn't happen. I took my old card out and tested the new card alone and my computer monitor would only run at 4-bit color with a res of 640x480. So then I put the new card in the first pic-e slot and the computer worked fine. I then took out the new card, and put the old card in the second slot, and it again ran with 4-bit color at 640x480. So, I've concluded that the problem does not lie with the either of the cards, but with the second(black in color) pci-e slot. I've run two 8600 gt's in sli before and they worked fine. I can't think of a reason why the second slot would force my graphics card to use 4-bit color at 640x480 res. All of the drivers are up to date. My psu has more than enough power to power the two cards. Would the problems perhaps lie with the bios? I am at a loss here. I hope there isn't a problem with the MB because it is a pain in the ass to take it out and try and get a replacement from asus.

Thanks,
Trey

btw, the MB is an Asus M2N-E SLI

Never mind, you can ignore this post. I was able to fix it by completely wiping my monitor and graphics drivers. After a clean install, everything seems to be working as they should. I feel so happy .