When I installed the QuickTime security fix (v7.0.4 for the records) on my laptop, I finally found out who caused this event log entry on my x64 box:

I didn't pay attention to the files copied when installing on my x64 box, but this incompatible GEARAspi driver is being installed by iTunes (which I still don't get why it is installed when I need QuickTime, but isn't this the kind of "packaging" that got Microsoft into hot water?).