I've got an Airport Express sitting on the other side of the house. For the majority of the day, where I usually sit my laptop, I have great signal strength. Occasionally, the signal strength will suddenly drop down to 1-2 bars during the day, and almost like clockwork at night. Has anyone else had this problem? There aren't any parental controls that might've gotten switched on through the router, but are there some for the airport card I might've unwittingly changed? My other thought is that the airport card connection to the motherboard is bad, or not securely fastened in, but I don't know how to check this myself. I've got a Powerbook G4 15" 1.67ghz I got about 3 years ago.