The Jeep service bulletin says to remove the Ignition Off-Draw (IOD) fuse for 10 seconds, then replace it. (See merlinTec's post for the fuse info URL.) Turn the ignition on, but do not restart the vehicle. The UConnect system should be reset and work properly.
If this does not work, the bulletin goes on to say the firmware needs to be reloaded from the navigation CD. This appears to require special equipment, so it looks like a job for the dealer. The bulletin indicates there should be a 1/2 hour labor charge.