The 2.4GHz band is a nightmare of mismanagement - or is that unmanagement?
http://en.wikipedia.org/wiki/Electro...nce_at_2.4_GHz
Wifi competes with bluetooth (though with AFH adaptive frequency hopping -from 1.2 onwards, bluetooth should keep out of the way).
Video senders are probably the most incompatible device, since they generate a continuous carrier.
Microwave ovens (when running) may generate interference centred around Wifi ch9, though the pulsed nature means Wifi can get some throughput past.
2.4GHz wireless keyboards or mice are another potential source of interference, which will also be close to the equipment