You can test them individually, just use one and boot into Windows and check the SPD with CPU-Z... make sure they both come up with the same specs. I read on Newegg.com a reviewer got some PNY Verto RAM, was totally bogus... the specs differed between the sticks.
Of course, if you're sure the sticks are supposed to go in certain slots for dual-channel and you can't boot then it sure sounds like a mobo prob... don't settle for having a busted component, especially if you haven't done anything to the mobo to warrant it being a lemon.
TJS
PS: Almost forgot, mobo makers usually color-code the slots to help identify which are the dual-channel slots... on my ASUS A8N32SLI, I believe its blue and black--slot 1-blue, slot 2-black, slot 3-blue, slot 4-black. See if your's is the same.