haha sounds familiar. Mine did exactly this and left me trying to file onto a dual carrage way from a slip road with no power - it was the first time it happened and I thought something had broken - it was quite dangerous. I'd just been booting it and it did a massive backfire when it cut the power, must have scared the life out of the people I'd overtaken.
Not only was the continued loss of power more dangerous than the original wheel spin, I know what part of the road caused it. There is a dip in the road and the car goes light, I was flat out and so it did a momentary spin and then as the weight came back on the wheels it was fine. I knew and was expecting it, TC did nothing at the point it happened, it actually kicked in about another 100 yards down the road ater the dip, just as I finsihed overtaking a car (luckily) and was about to file on...
anyway, suffice to say that was the 1st and last dodgy experience with stock TC of that nature. I switched it off from then on and fitted RLTC as soon as I could, never looked back since, the two systems arn't even comparible at all - get it!