If you want to hear something funny, the way the tech explained finally finding the problem:

TECH:"well sir, I brought the car up to running temp and it exhibited none of the misfire problems we saw during previous diagnosis.( they had the car for 4 days) From the results of previous tests we had narrowed the problem to the ECM, so I performed a test on it."

ME: "What kind of test?"

TECH: "Well, I hit it pretty hard with my hand"

ME: "So you are saying you punched it"

TECH:[long pause]...basically, yeah"

ME: "and the results were?"

TECH: "It started misfiring"

ME: " can you be sure that this is the problem"

TECH: "We can't find anythig else wrong and if it isn't the problem, you won't have to pay for the part"

ME: "Enough for me, order it up"

It took a few days to get the part to NJ, supposedly it is a 'controled part' and isn't stored at the regional warehouses. They put it in on Tuesday, spent 2 hours testing it and the car is running great, actually better than it has in a long time(idles great, really smooth acceleration / decceleration and great gas milage). I have driven it to work two days in a row averaging 75mph for 70 miles and no problems.

In talking to the parts guy and the service manager, these problems don't occur too often, they said that most ECM's just die or have so many symptoms that it is evident that the problem is the ECM, it isn't very often that they have a weird problem like this.

I would encourage anyone having these kinds of problems to break out their service manual and check all possible circuits related to the problem. Unfortunately this didn't work for me (and after toying with it for so much time, I was superbly fed up) , so I was stuck with sending it to the dealer, which in the end got the problem fixed, even if it was a $650 part and $300 for diagnosis...in the grand scheme of things, the cost per mile is still pretty low for these cars, with almost 200k miles on my car, I can't complain one bit...