stalling when stopping?

hey everyone, need some help diagnosing this one. I have a 99 A6 auto, v6, quattro w/ 104k miles. What happens is when the car is coming to a stop, it will stall out. sometimes it will start right back up, sometimes it will take a few tries.

a complete fluid change and tune up has been performed, and the problem still persists. anyone else had anything close to this? any ideas?