Sending data to serial port using Processing IDE (Debug works but run doesn't)
I'm confused.  What language is this?
Anyway my guess is that you aren't terminating what you send to the Arduino properly (would have helped to see the Arduino code).  The reason I think its this is you are sending a zero after you number.  How does the Arduino know that the zero is not part of the number, do you mean a null or new line?