Electrical fields are not the only form of EMI, or Electromagnetic Interference. Magnetic fields can also cause problems with electronic equipment.
One typical magnetic field which can cause problems is slowly disappearing. The venerable CRT (Cathode Ray Tube) display is rapidly dying out as consumers favor the slimmer, less weighty, power saving flat panel LCD displays. This is good because the old-fashioned CRT display generates very powerful magnetic fields which can interact with your computer.
The primary mode of interference caused by magnetic fields is the induction of spurious electrical signals into the cables and other components of computers. These magnetic fields can cause errors in reading devices such as diskette drives (the few that are left), CD and DVD drives and serial devices that have external cables. This type of problem can manifest itself as CRC or read errors.
These types of problems can be resolved or ameliorated by moving the monitor as far from the computer and its other peripherals as possible.