Hi Norsk,
First things first, the 4x4 gear box is very nice

Unfortunately the symptoms yours is showing are signs of a gearbox out job, and a rebuild. You could look at the gear lever rubber boot,as sometimes these can be tight and pull the lever out of gear, or the detent for the gear lever could be warn. Otherwise it's a case of just living with the box as it is.
It looks like an amazing area you were camping in by the way

Brian