FOLDERS ARE MISPLACED IN AN NT SERVER AN

Did this ever happened to anyone. For some reason some of the folders on the shared drive of an nt server are being misplaced and they are found in some folders that the have no business of being there. It happned on a win 98 desktop too. I had to search for each folder and bring it bring it back to its original folder. Could this be a virus thingv or somethingelse. My norton is up to date. Help!!

Thanks