Well that's odd. If that is happening I would say something is not right.I don't think that would be cool. I have never seen a case where the task manager didn't know the cpu was in use unless it actually wasn't processing at the time. I use a thread process utility and since it has no threads either, no cpu time and no listing in memory. I'd say it was gone :)

No need to think outside the box....
    Just make it invisible.