If you're on Windows, you might need to change a registry setting to stop Windows from polling your parallel port. See http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1142106610 for more details and some other things to try.
If you're on Windows, you might need to change a registry setting to stop Windows from polling your parallel port. See http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1142106610 for more details and some other things to try.