python and potentiometer

Hey there,

I've been having a bit of trouble using arduino with python. I don't have a lot of experience with neither of both, but still I've able to get results as I wanted them. I have the latest StandardFirmata uploaded on the board and I use the module on the python side(which seems to be an update of pyduino v1). I also tried pyduino v1 and v2 and I tried the ShortMessageSystem and Messenger on on the arduino. Everything gives me the same result, I get only zeros when I try to read from the potmeter. Digital is now problem. Here's the code I've tried, which is just a little adaptation from the examples that came with

from firmata import * 

a = Arduino('/dev/tty.usbserial-A1000fOa')
a.pin_mode(2, INPUT)

while True:
    print a.analog_read(2)

I thought that it might be a physical problem with the arduino, but when I load the AnalogInput example onto the board I have now problem at all.

anybody any ideas?

thanks in advance,