Sounds like you are getting channel interference. Within the 2.4 gHz range, there are small frequency changes so that your neighbors (or your phone's) router doesn't interfere with your. Sign in to your Linksys router and go to wireless settings. Change the channel away from 6. Many routers are set to default at 6. If there is another channel designated, such as 1, then try channel 11.

 

Thank god I'm not the only one with this happening. Did we find a resolution to this? This is insane.

 

It solved my problem (changing channel from 1 to 11).

UPDATE: oops, the problem showed up again... trying to change the wifi encryption settings instead.

 

I don't understand - how can you get 3G and WiFi enabled at the same time on your phone? My phones (D2G and DX) do not do this. At worst there is a short overlap of a few seconds while the 3G comes on and the WiFi goes off or vice versa. I also use the same Quick Settings application via my notification bar but only my my D2G. My wife is the DX user and does less tinkering than I do.

In theory if both are active - you may be bridging your WiFi network and the 3G which will confuse all the of machine in the network as there will be two outbound default routes and multiple IP address schemes in use.