One week old new 15" PowerBook w/1G RAM and 7200 RPM drive. For one week the Airport has been working fine on our home wireless network. With no changes to anything, the Airport signal has gone to nothing today after working fine for one week--i.e. it no-longer detects our home network. No bars on the signal strength indicator. Our Windows XP PC on the same wireless network is still working fine with maxed out signal strength. The laptop is two feet away from the PC and both are 12 feet away from the wireless router. I can hold the laptop one foot away from the ZyXEL B-2000 wireless router and nothing happens. I have tried resetting the PMU, repairing permissions, deleting the Airport preferences file and re-entering the wireless network info with no luck. All updates have been applied including the most recent Aiport update. Any suggestions?