Gearbox fault warning message

[SPS]

Can anyone help re the above please?
After my 2002 RR has been standing for a few day the above light warning appears and the car sets itself into 3rd gear. It will then sort itself out and revert to normal drive after a few moments or so!
It's been back to the dealership at least five times. The last time they put a new battery on it thinking that this would sort it - it did for a few days and now the fault is back. They have told me not to worry as they will sort the problem - well I'm starting to wonder! Don't get me wrong - I can't fault there levels of attention and free hire cars etcetera but this has been happening for a couple of months now. They have also assured me that even if this problem is not corrected after my warranty runs out that they will ensure that it will cost me no money. A plus there then. The problem is that I really purchased the RR to tow my boat and I'm not sure that this will be ok to do with this problem,
Any help much appreciated.
Despite this one problem I really love the RR.
Cheers
SPS

[Mr Tj]

Not to sound alarmist, but I had an interesting twist to the whole 'GearBox Fault' message scenario this summer. My Alternator had failed overnight whilst on a 2-day drive PA-IA, and after about 45 minutes of driving down I-80 in Indiana, I suddenly got 'GearBox Fault' on the display, and it felt as if the car dropped into Neutral, which made sitting in the outside lane in freeway traffic rather exciting. Recovered to the downtown Chicago stealership (talk about snooty sales people - next time I'm going to ask for a Real Land Rover dealership if I need one on the road) where the bad news included that the battery had blown whilst waiting for the tow, and the ignition coil was also scrap.

I've known bad batteries to cause all sorts of weird effects, particularly on the earlier Lucas electrics, not sure of the Bosch systems. Prior to this occurrence, I would blow a battery about every 18-24 months for no known reason, hopefully new ignition coil / alternator combo has fixed that issue.