Is it possible you are moving the laptop too far from the signal? Too Close (yes you can do that too)? It might be a lamp (certain flourescent bulbs will kill a WIFI signal). It could be a garage door opener your neighbor is using in the alley behind your house (seen a garage opener restart a wireless gateway before!). Set the laptop next to your desktop and use it...does it ever drop? If not, then it sounds like the signalling isn't reaching your laptop 100% of the time!