It's a bit hard indeed, since you can't just borrow a friend's CPU and try it on your mobo (thanks to 1156's newness). Your best bet is to return the motherboard first, try it out with your CPU. If it still doesn't work, return the CPU and try the new one.
How determined ? Are you running Asus Probe or something to monitor ?
Anything in Event Monitor ?
How was OS (which one BTW) installed ? ... fresh install or already on HD from old computer ?
I used Asus Probe II and the bios temp monitor and both showed the CPU at around 36 degrees idle (stock cooler).
Nothing in the event monitor, and I managed to get it to run long enough to do a fresh install of Vista 64 running one of the DIMMs in one of the memory banks (b1).
Once I flashed the BIOS to 6060 it started crashing a lot earlier.
Either way, I just now managed to snag a DDR3 4gig corsair XMS kit, and the system seems to be running fine (90 minutes and counting, knock on wood).
I guess I'll just send the mushkin memory back and get me some store credit.
And I'll be damn sure to check the QVL for my motherboard next time, heh.