I know this is an old thread, but I have had the same issue crop up whether I open and close files manually or programmatically.

I did not have Google Desktop installed, but after tons of searches and much deep thinking :-), found another culprit that might assist others with this issue. Namely:add-ins. I had the Adobe PDF Maker add-in enabled. Adobe has gotten quite invasive recently with new versions coming out seemingly daily.
It even rebooted my box overnight once, so I don't see it installing an add-in by itself as out of the realm of possibility.

Anyway, I disabled that add-in and the isse went away.

Just an FYI.