We have also done several of these and Just done another one today, This problem must be caused by something upsetting the BCM as a simple reboot cures the problem, So its nothing to do with the connections on the BCM. ( More like just powering it down and rebooting it )

All we did was Disconnect and reconnect the battery, Cycle the ignition 4 times, The drivers door was open and seat belts not fastened the buzzer sounded to say that it was in programming mode and it bleeped again when the remote was pressed.

Job done. H.T.H