Reset Tiptronic, TCU?

[12dan34]

I'm still having issues with the tiptronic when cold on my 1998 996 C2. Is it possible to reset the gearbox? Where i used to live we had a gravel driveway that was on a slope, when i reversed the car off, it had so much torque that using the brake pedal to control speed meant the front wheels would lock as the rears kept turning and literally dragged the locked up fronts across the loose gravel. Eventually I learnt to leave the brake pedal alone and i used the hand brake instead as this helped to slow the rear wheels instead of the front and did the trick. However about this time i found that once I'd driven off (forwards!), at low speeds the rpm would be a little erratic, almost like it wanted to change gear but didn't (I've tried to video this to demonstrate). So I'm wondering if my hand brake trick might have upset the tcu settings, and now i need to reset...? Any ideas please? The Indies I've taken it to have changed the maf and the throttle body, thinking it's an engine issue, this has done nothing other than cost me money and I'm now convinced it's transmission related.