I am not familiar with that board, but I know it's a popular one. Have you updated to the latest BIOS for that board?
I am not sure if it's a directly similar board, but Corsair tested 20 of these kits in an A8N-SLI Premium and each and every one worked fine. They were also using an X2 4200+, which makes this even more odd.
You may want to read Redbeards last post in this thread
regarding the memory. It could be a BIOS issue, I am not positive. He ran his X2 4200+ at 2.75GHz though.