What I would do is take a look at this:
http://www.turnermotorsport.com/cata...cu_removal.htm See if you see any residue from coolant (will be yellow, red, or green). If that's the problem, get a new transmision ECU online or from a junk yard. This could be something worth paying BMW to diagnose however. Shouldn't be more than 1/2 hour of labor for them to hook it up to a computer and pull codes. Or you could drive up to Jersey and I'll scan for you
... I might be going to NC for a few days next week if you could make it up there too
.