I know this is an old thread but in case anyone is interested....
From the Guitar Rig manual:
Guitar pickups are very susceptible to hum, light dimmer ?hash,? and the
interference generated by computers and monitors. LCD monitors create
less interference than CRT types, and humbuckers are less likely to pick
up interference than single coil pickups. Piezo pickups, like those used
in the Line 6 Variax, do not pick up this interference.
As you play with GUITAR RIG, always position your guitar so it picks up
the least amount of interference. GUITAR RIG?s Noise Gate can help get
rid of some interference, but it is not a substitute for orienting your guitar
away from sources of interference.