A (CRT) monitor uses electromagnetism to steer an electron beam, so yes waving a magnet in front of one will definitely have an effect.. even permanently - there's a metal plate with holes (or slits for trinitrons) for the beam, and it can get permanently magnetised if you're too abusive with the magnet. That doesn't mean that _everything_ with electrons can get damaged by a magnet..

On-topic: I'm totally baffled by the problem, as I just don't see it when I do exactly as described in the previous posting. As soon as I remove the cable the usb icon goes away and everything is back to normal.