not chattering like a lock diff, you can just feel it through the sterring but no sound coming from the tires..
Jezboosted, I think you might be onto something in suggesting the front cv's, The previous owner had replaced the boots before i bought the car so that would explain it.. ill jack it up on the weekend and inspect.. probably not worth replacing them unless they get noisey..
And no the snow button / center lock is definately disengaged,