I have recently upgraded my Motherboard and am now looking at RAM. I have an ASRock N68C-GS4FX Motherboard and a AMD Phenom II X4 940 Processor. I have used the CrucialPC system scan application, and in the memory window it does suggest upgrading to DDR3 RAM (as it would fit in the Motherboard), but I was under the impression that my Processor would not work with DDR3 RAM.
That motherboard supports both AM2(+) and AM3(+) socket CPU's, hence the confusion. AM2 CPU's will only work with DDR2 RAM. AM3 CPU's, on the other hand, are backwards compatible and will work with DDR2 or DDR3 RAM. Thanks @sunk818 for the clarification.
The AMD Phenom II X4 940 is an AM2+ socket so it will NOT support DDR3 RAM. This is because you have a hybrid motherboard.
The AM2+ Phenom 2 x4 940 does not support DDR3. Only the AM3 version Phenom 2s support both DDR2 and DDR3, because they have dual memory controllers built-in.