well this is just my personal expirience, but at at least 2 times this has happened to me, i started my car pc came out of hibernation, the gps antenna led blinked which means it's locked, but yet iGuidance nor RR would detect any satellites,restarted the pc nothing, checked the comm ports and they were correct, so i closed Xport and changed the comm port in iGuidance to the receiver directly and BANG 9 satellite lock immediately, rescanned with Xport changed comm ports again and then it started working perfectly.