I'm getting my new tyres this afternoon (Latitudes) so will give a report on those once fitted, if there is no improvement with this strange problem I will be off to the local indy BMW Mechanic (he has all the bmw computer equipment), I will probably get him to check the transmission also while there even though it seems ok shifting, the shifting distance could probably do with a re-program on the D setting though, I will also get him to change the transmission fluid and check the driveline and rear transfer case belt as recommended by tou guys for good measure...

It's quite hard to re-create the problem so I'm hoping a sofware update will do the trick...

I tried the transmission reset mentioned above and the car felt totally different when driving it, more aggresive (It was a nice change) however the next time I got in the 4x4 it was back to driving in it's usual manner which confirms what I posted above...