My rig works file with one video card, but once I put a second one in, it seems to not even want to put a display out.  It seems like it will boot fine, it just seems to not want to display, which is somewhat important considering I still need to set up the rig. 

It's running ubuntu, so my next step is to try to boot and then shell in, see if I actually do get some sort of boot besides fans spinning. (note: appears not...  Just fans spinning afterall)
Anyways, I'm wondering if any of you guys have encountered this issue and have gotten around it.  Here's my motherboard: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131013
I'm running 2 XFX 5770s (here: http://www.newegg.com/Product/Product.aspx?Item=N82E16814150539 )

Thanks for your help!