You can try following
this post, see if maybe your phone somehow accidentally shipped with aGPS off.
Try running QuickGPS when you're connected to WiFi,
Do you have a data plan at all? Sprint isn't supposed to sell the device without one, but hey. It's Sprint, anything is possible. Without data, I guarantee the aGPS will cause a GPS program to fail locking sats.
You can also try using "GPS Utilities" which can log NMEA data to a file, to see if there is even the briefest of signals that your program is not indicating. There is another user that had a working GPS previous to a ROM flash, who cannot get his to work now so don't feel alone in your search.
Also, Google Maps requires you to select the 'Use GPS' option before 'My Location' will work. It will indicate if it is attempting to lock, and how many if any satellites it has locked.