Exact same for me Ken, which is why it has been in 2 times to get fixed and why the Head of MINI Tech is looking into it... I sometimes think from the tone of your posts that you think I just put my car in for silly little problems.... This problem definately sounds like an air lock of some description, therefore not a good situation..
I still have a few other problems that I haven't bothered telling them about yet as it's been 4 months and I'm still waiting on the original problems getting fixed...:(