Initially tried disabling Windows Defender and EFS. I really had no idea what was causing it. And the few threads I found online didn't seem to have any more of a clue than I.
After taking a few minutes to think about it the next time it happened, I recalled the Aero Peek function and some of the other weird stuff that Aero does. Perhaps a graphics problem? So I'm running an Nvidia 8600 GTS from XFX with 256 MB of memory. Driver was 100% up to date directly from XFX for Windows 7 64 bit. Then I disabled Aero and went to the Windows classic view.
Have not had the problem since. That leads me to believe it is either a driver problem, a video card problem, or an Aero problem.
Today I downloaded an updated driver and have turned Aero back on. Now it is merely a waiting game to see if the problem has been actually fixed or still remains.
EDIT: Nope. Still not fixed. Turned Aero back off. Back to Windows Classic.