Kinda have a similar thing going on here at home and actually I have a repeater in the house for T-Mo / Sprint and Verizon EVDO. (That combo just works out with the frequencies it operates at). My house has aluminum siding, it turns my house into a RF trap and so signal has a hard time getting in and out of here.
Normally I go out to the garage which is attached, and doesn't have the siding blocking the signal. The router is on the other side of the house so by the time I get out there, the signal is low enough it's trying to switch over to EDGE. That's probably why I don't have much trouble with it, found a pattern that works and I follow it every time.
