Was at a filling station the other day with a bit of a steep entrance but as there was a queue I had to wait on the incline but my MCSa started to roll back even in M1! Should this be happening? It was the first time it happened having been stationary on similar inclines before.:(

I wouldn't think it was anything to worry about, if your 'clutch' held the weight of your MINI whilst stationary it would soon burn out - I take it you were not using the handbrake.
If you want it to hold just apply a little pressure on the accelerator and then it should hold in position for a short while.

Thanks, it was just a bit disconcerting when it happened as I didn't notice I was moving back until my wife panicked!!:p