For some reason, my MacBook keeps disconnecting and reconnecting from my home network. Browsing the internet, accessing network files, listening to iTunes sharing, all of these things are interrupted by the AirPort disconnecting from my network and reconnecting moments later - and by moments I mean like 1 or 2 seconds. In the Finderbar, I see the Airport symbol have all the bars completely full, and then all of a sudden drop to empty, and then a second later become completely full again. Clicking on this shows Airport: Scanning..., but I think it's just because I click it that it looks for networks. How do I get this to stop? It's incredibly frustrating.