Rhodes Chroma Polaris

Hi 

This is my first post. I've owned a polaris for about 2 years now and I think it's a great instrument with much unexplored potential. 

Trying to interface it with a computer is proving difficult though. I'm using 2 separate approaches, the first through an edirol UM1 with Pure Data, the second with touchosc and a missing link direct from an ipod touch. 

I can control the parameters on the polaris via cc with both methods. But both methods produce sustained notes unless I set the volume envelope delay on the polaris very low. The polaris is forced into playing in mono (from the keyboard) by both methods. Also noteon/noteoff pairs give 2 noteons on play and release.

I've been through the midi section on the polaris manual and have experimented with different midi settings, but am not getting anywhere: I'd be grateful to anyone could offer any advice. 

thanks

Huw