Well, you don't exactly know it's the motherboard. Some "tech" in an IT department suggested it may be the motherboard. Unless they tested the CPU and memory in another, known working machine, then it's just a guess, because they certainly have no diagnostic equipment to evaluate hardware at that level.
Did you actually power up the motherboard with the CPU installed, but no CPU heatsink? A few seconds is all it would take to trash the typical CPU in that scenario. Did you mention this to the folks at mWave?
Always keep packaging for at least as long an item's warranty. After 15-30 days (depending on the vendor's policy) you'll have to deal with the manufacturer for any warranty issues. And not many of them will cross-ship. It's also handy to have when you upgrade components and sell the old ones.