remote printing with cups

[richard.bown at blueyonder.co.uk]

Hi
I'm trying to use cups for remote printing, both machines are on the 
same subnet, the machine used as a cups server
has published the printer and is seen by the other machine.
Using Firestarter port 631 is open for both tcp & udp, but the print 
request is beig refused.
Are there any futher security layers in Ubuntu 8.04 that need to be changed.
TIA
Richard