Wireless Connection Instability


I have a new 1.5 GHz 12" Powerbook G4 that I got in March. I have Tiger with all of the newest updates. In the last month or so, the wireless connection has tended to randomly increase and decrease signal without moving the laptop an inch. Another laptop I have sitting right next to it is not havign this problem, so it is not my router. The main question I'm asking is whether this may be software related or hardware related. It is still under warranty, so I am not worried either way, but I'd obviously rather not ship my laptop off if it is not necessary. Thanks.