Hi Roger,
Maybe I wasn't clear enough.
I already have the 2 sites running on the box, one on port 80 and one on port 81. This works fine for html files.
Any php files work fine on port 80, but do not work on port 81.
Looking at phpinfo.php I see that there is a Server_Port setting which is 80.
I don't know how to change that setting, but more importantly, can it be set to both 80 and 81 at the same time?
Cheers,
Sean