We had that problem with computers when having the metal shielding off the cases. Every time someone in the vicinity got a phonecall on their Motorola 2880 (random model number, can't remember but one of the really old ones) the computers would bluescreen. This was at hackernights with all sorts of different computers running windows 95. If they had the metal shields off, many of them would bluescreen on phonecalls. Shields were off for having more cooling from external sources or friends helping with installing stuff or whatever, and the problems would go away when the shield was on again.