I bought the MB two years ago and put two 1GB Corsair TWIN3x2048-1333C9DHX (CM3X1024-1333C9DHX) in it. It has worked fine. I just bought two identical Corsair memory sticks and now the MB beeps three teams(memory failure) and fails to boot. The memory sticks are the same except the old ones are stamped version1 and the new ones are stamped version 3.1.
My first thought would be to test all the memory individually to check they all work.
then i woudl put the 2 new ones in adn see if it boots up with them.
then i would update the BIOS.
then test all four together and see what happens