I also have this problem. Sometimes notes are hanging when a lot of aftertouch messages and note on/off messages are sent to the Pro One within a short amount of time. When I disable aftertouch on my CS6x I do not have hanging notes anymore.
Noah user list ... that's a good idea. I just got many helpful tips from all of you in this forum. I have my Noah EX for three months now. I hope, I can give back some helpful tips in future.