Transmission Slip Out Of Gear problems of the 2008 Audi A3

Since purchase as a cpo in early 2009, my 2008 Audi A3 and its dsg transmission have exhibited irregular and dangerous shifting behavior. The transmission surges unpredictably at low speeds, particularly in 1st or reverse with brakes off and little/no gas. This low speed surging behavior is dangerous in stop-and-go traffic as the car often unpredictably jumps towards other vehicles. Also on several occasions the transmission has completely dropped out of gear and failed to re-engage for approximately 1-2 seconds. On one occasion, this pause occurred during a left hand turn across opposing traffic and nearly caused a collision. In summer 2010 Audi replaced the mechatronic unit under warranty and reflashed the dsg. This fixed the issues for 1-2 months, however the problems have since reappeared. It's seems clear that this line of transmissions have persistent and possibly dangerous problems.