Does anyone else have any signal strength issues with the latest series of powerbook g4's? I have a 1.5ghz machine that seems to lose signal strength just by going upstairs. I have a wireless G+ Speedbooster Linksys router, and I even purchased a Linksys range extender. The extender seems to help a bit, but still not the performance I would expect from my otherwise excellent Apple product. Thanks for the feedback ahead of time.