[maxmsp] Arduino2Max frustration

So for a couple of weeks now I have been trying to make Max talk to my Arduino. The frustration is that Max is obviously seeing the board as the red upload light flashes when i start the Arduino2Max patch.  But nothing else will work. I cant receive any digital input or send any digital out.

I'm working on a Mackbook Pro with Max 4.6. As far as I know I have installed all the drivers.  

I have run out of ideas about what to try next - any suggestions would be great.

Thanks