I've had issues with avdi on later (01+) TT clusters, support eventually told me they didn't support that cluster. A 9s12 programmer from ebay did the job. It did require soldering to the board. The software provided with my programmer did not correctly change the mileage or display the pin.
good bit of info. i only ever solder them. i used to attempt obd using different tools and finally gave up. soldering is dead on exact 100% of the time.