Windows 7 issues linksys router

I'm using a surfboard cable modem, linksys wrt54g vonage router, and ai just replace a linksys WAP that died with a linksys wrt54g2 router as my WAP, wired to the router, for extra signal strength on the other side of the house. All settings aear correct- no DHCP service on the WAP ame channel, etc. In fact, my xp laptop and vista laptop receive strong signal just fine. my windows 7 desktop loses connectivity whenever the WAP is powered up. unplug the WAP and my 7 machine finds a signal from the router. What is up?