Biostar TA790gx A3+ Memory socket problems?

[thefreddyfinger]

Heya Folks, I'm bran new here and I seek some brilliant minds to assist me in figuring out wtf is wrong with my motherboard if at all possible.

I have kind of a strange problem actually. My system is highly unstable due to (according to the LED indicator and 0x000 error says) a memory error. I have 4 sticks of OCZ Ripjaws DDR3 1600 ram, however I can't use all of them. If I leave 1 stick in the board, is works fine. If I add 2, 3, or 4 it becomes highly unstable with blue-screen errors, and various other software freezes/crashes. If I put all 4 sticks in, then start it up and let it either crash of shut it down (whichever comes first) then remove 1 and start it back up, it seems to work perfectly. Yesterday it crashed again and now only accepts 1 stick without crashing no matter what I do. I've tested all 4 sticks in another computer running nearly the same set-up, but with an ASUS board and it works fine. could this be a bios problem? I sent it in to Biostar on an RMA and they sent it back saying there was nothing wrong and charged me for shipping, so I doubt it's a physical defect.

I'm running an AMD Phenom II x4 955 Black 3.2ghz processor, 8 gigs of OCZ Ripjaws DDR3 1600 ram, and an ATi Radeon HD5770 gfx card in my Biostar TA790gx A3+.

Any Ideas?