[Syph3r]

Unless you flashed a new Radio. That would definately affect your signal.

Heres what I would do if I were in your shoes:

1st Flash back to the stock sprint rom and radio...see if that changes anything.

2nd (which might be easier than the first) Find someone else with a sprint phone and see if they get EVDO at your house. That would be a sure fire way to know if your phone has a problem

Its not unlikely that the engineers in your area shifted a towers transmitters by your house. It sometimes happens when they create new towers, the grid has to get re-aligned or shifted because of another area with a deadzone.