Nick ,
Yes the clutch doesnt seem to slip every time. It happens when the boost kicks in. Sometimes its fine but occasionally the revs climb without the car accelerating much and then it seems to get it together and go. I assume its on its way out and will simply get worse until either I or Audi replace it. Looking at the costs shown on here I will probably go down the MTM clutch route. Presumably this clutch is supposed to be able take the extra go from the chip.