Hi,
Unfortunately I don't have the previous bios version. I tired one stick at a time and the bios recognized that there was a decrease in ram to 2 gb. I switched the sticks around to the blue DIMM 1 and DIMM 2 slots and it didn't make a difference. I installed the sticks back in DIMM1 and DIMM2 and am back to 4 GB.
Thanks