One user (sorry, forget who) noted over in that other thread that this seems to happen about once a year on average, and is merely a glitch in the rootkit scanner. For any given user the specific file warned of seems to be more or less random, so it's not a FP problem. It does, however, seem to be particularly sensitive to drivers (.sys files) for some reason.
While it's remotely possible, of course, that you really did pick up an "iffy" driver somewhere, you can almost certainly ignore these warnings.