WNR1000v3 bandwidth drops when wireless turned on

[TheBluePhoenix]

I generally use my router with wired computers so I usually leave the wireless tuned off. I typically get bandwidth anywhere between 10 & 20 mbps up. When I turn the wireless on (with the button on the side of the router) the wired bandwidth immediately drops to about 2 to 4 mbps or less. This happens without adding any additional wireless or wired devices. When I do attached a wireless device it gets only about 1 mbps up. When I turn the wireless off the bandwidth on my wired computer returns to normal.

Any ideas? Thanks In advance.

My firmware version is V1.0.2.28_52.0.60NA