Gigabyte motherboard overheating?

I bought a new MA770-UD3 motherboard from Gigabyte and it's running at 78C in one location. I've RMA'd it once and they "repaired" it, but I'm still running hot. The CPU is running cool, the case is cool - everything except one location on the mobo. At this point, I'm ready to take the thing out back and stomp on it and just call it a moderately expensive lesson learned but any ideas? (The only symptom of running hot is that it shuts down when I do anything intense, such as open a game, etc.)