I don't think it's your mainboard. What operating system are you running? Did you install the drivers that came with the muvo? If you do think it's the mainboard I'll swap you for my epox 8k3a. lol I love my mainboard, so fast, so stable, so uber! I have heard of some problems with the a7n8x's early revisions. But I think this is software.
Treat your body like a $600 car. God didn't intend it to last so use it. Run it into the ground!