Canadiancanuck- this problem you had sounds exactly like what my guy found on a brand new 09 and Chrysler was very aware of the problem..
this was on a 09 rt... chrysler tech support said that they had several toque converters from a supplier that had rust on them and were cleaned up with emery cloth..
they had us ship the complete trans to the engineers...if it happens again i would bet this is your problem...
thank god all of us that purchased 08s the cars are flawless....good luck.. Joani