Nissan Patrol 3L Turbo Auto Transmission

I have a 2001 Patrol 3L Turbo with auto transmission and I recently had a problem with the auto which seems a bit odd and also had the NRMA technician puzzled.

The car had been operating normally and I had just parked it and turned off the ignition, I then tried to restart the engine however it would not start. All the normal instrument lights came on but the engine would not turn over and the starter motor would not engage. I called the NRMA and the technician checked all the usual items but could not find any faults. The problem was eventually traced to a blown fuse (7.5amp) for the auto transmission, I didn't even know it existed. Upon replacing the fuse the engine started but it raised the question as to why it had blown in the first place. The NRMA tech had never seen this problem before and could not shed any light on a possible cause.

The problem may just be a one off incident but I am interested to know if anyone else has experienced a similar problem and whether it is a sign of some other bigger problem with the transmission.

I would welcome any comments / suggestions.