Has anyone heard of this - I am losing my mind with this car!

2000 ML55 w/ 65K miles. Car started stalling, brought in for service and had crankshaft sensor replaced. Problem came back with increasing frequency. It would stall when driving, I put it in neutral and it starts back up but when I put trans back in drive, it does not seem to catch for a minute, anbd just revs like it is still in neutral. MB next replaced stop lamp switch, which was the only code that came up, which did not fix the problem. Then MB tells me that the transmission seal leaked and fluid got in to the main wiring harness and all the way to the ECM. Thankfully, I bought an extended warranty from AAA, the repair was $9K. MB was actually great about working w/ AAA and coordinating the repair.

BUT after weeks without the car (the ECM had to come from Germany), I have had it back for 2 days, THE SAME PROBLEM IS BACK! The car is back at MB (it stalled twice on the way there). Now MB tells me that they are driving it and cant find anything, there are no codes.

Has anyone ever heard of anything like this? Any ideas? It's making me nuts!