Hi
I am teaching pd + arduino at medialab madrid workshop (http://www.medialabmadrid.es) and I did a Pduino 0.2 test with my 25 students (divided under win, intel mac, ppc mac and linux).

We all uploaded Pduino 0.2 firmware to the board and then we run 0.2 arduino-test.pd under Pd extended test5.
Nobody  was able to interface arduino under four different OS.
We all were able to connect to the serial port. We tried to set a LED on in Arduino pin 13. When we pushed serial data to the board the RX LED was on but the pin 13 LED was still off and the same with the other digital or analog pins.

We then tried Pduino 0.1 and it worked.

Qq