I have this:http://www.corsair.com/memory-by-product-family/value-select-memory-upgrades/cmv4gx3m1a1333c9.html
2 of those, total of 8GB. The RAM had no problem. Tried it in other PC and it was showing fine as 8GB (2x4GB). It was a motherboard issue and it was sent for RMA. In dual channel, it was recognizing both DIMMs but the system was getting half of the RAM. In single channel mode, it was showing full RAM but it is pointless to go for single channel considering that the negative effect especially in GPU will be big enough.
They replaced it with a brand new A75MA-G55. In the beginning I was afraid that the new m/b will also have the same issue but I was wrong. And it worked with the original BIOS, didn't have to upgrade (although I upgraded later).
You should try yours in single channel, one DIMM in black and one in blue socket. See what happens.