Many thanks for your help James :D I don't know what you mean by "xterm (you meant that right?) session". I ran them in Terminal and got the following: Code: Last login: Sat May 24 17:19:42 on ttys000 Pauls-MacBook-Pro:~ Paul$ echo $DISPLAY /tmp/launch-KrFGwM/:0 Pauls-MacBook-Pro:~ Paul$ echo $OSTYPE darwin9.0