WiFi Gurus please help

I've tried searching the forums for an answer but have come up with nothing.

well here's my situation, I have a linksys wireless G router (WRK54G) that is connected with Verizon DSL (westell 6100 modem) and when using my XP laptop everything is great but when using my 15in PB, my connection will drop on and off. I'll be connected anywhere from 1-5 minutes then my connection will drop for a few seconds then pickup again. Needless to say it's been a real pain and I've tried changing around various settings with no luck. Any ideas as to how to fix this pain in my side.

Thanks in advance!!