Gigabyte Z68A-D3H-B3 Random USB Failure?

I've been having a problem where my USB drives fail randomly, without much warning, or recognition from the system. It happens during all conditions, playing games to surfing the web or whatever. The system doesn't recognize that they disconnect and there's no sound played. It occurred once while I was typing this. The problem necessitates a reboot to fix, but the problem reoccurs. They all failure simultaneously, freezing my keyboard and mouse as well as disconnecting my External HDD. Sometimes I can plug the mouse and keyboard into the two front seated USB ports and they'll work for a short time before eventually failing. Sometimes the mouse and keyboard will hang for a few seconds at a time before shutting down completely. It's not a system problem, as games will continue to play and everything goes along like normal. Sometimes, it freezes as if I were continuously holding a key down.

IN any case the problem is spotty and somewhat random. I'm really hoping that this isn't a serious hardware failure.

My build is about 1.5 years old and I'm running Windows 7 Ultimate 64-bit

The problem started last month. I moved the computer from my dorm to home over winter break, and for a while, I thought the problem had gone away, but it came back early this week.

I've tried:
Updating BIOS
Monitoring heat; it doesn't appear to be a problem.
Reseating CMOS
Investigating event viewer.