DFI Lan Party Pro Aggravation

I've recently built a system around a DFI Lan PArty Pro 875B board and I can't figure out what it's doing with my ram. I have four 512 meg sticks of Geil Golden Dragon ram. When I first started the system up, it was only reporting 1.5 gigs of ram and stating "single channel mode with performance acceleration tech. enabled". Some folks at another board mentioned setting the BIOS for dual channel operation, but there's no clear-cut instructions in the manual as to how to do this.

I subsequnetly wandered into the advance chipset setting on a recommendation there, and by disabling the bandwidth setting, I was able to get the motherboard to go into dual channel mode and see all 2 gigs of ram. Or at least, I though that's what did it.

I just installed a new graphics card, an ATI Fire GL T2, and when I rebooted, the system is back to reporting 1.5 gigs of ram again and back in "single channel mode with performance acceleration tech. enabled". I check the advanced chipset settings and the bandwidth setting is still shut off.

I don't understand what's going on here. Why would installing the new card put this system back into single channel mode and not see 512 megs of ram? Does the graphics card installation have anything to do with it at all? I can't imagine why it would in the first place.

This is really annoying and aggravating. Does anyone know how to set this system so it sees the ram and runs it in dual channel mode? Thanks for any help with this.