Yes this sounds exactly like my problem.

I am using a ProLink Wireless G Router. My PC connects to the router via ethernet cable and a second PC connects via Wireless USB dongle. The connection is perfect and never drops UNTIL I start Limewire. Then I cannot connect to the Internet with IE or Firefox, or my email etc.

This only happens when I run Limewire and I have to shut down LW and wait about 2-3 mins for my internet connection to come back online.