mine did it, it turned out to be the 19mm bolt located just below the pully on the supercharger (its propa shagged), tho i had to remove the charger to tap out the hole again and i also used a new bolt as the old one was fucked.
mine's fine now and hasn't moved at all,
i'd tap the holes out again if your'e getting movement, think the threads are M12
cheers Tom