Vista Firewall slows up printing

Hi,
I've got a Canon LBP5200 laser printer. Since getting a new PC with Vista
Home loaded I've had problems with the printer.
Got the correct driver from Canon installed and the printer works but takes
forever to spool & start printing.
Checked with Canon support and all the printer configuration settings are as
they recommend - they couldn't recreate the problem but suggested a firewall
might be the cause.
If I switch off Windows Firewall it works like lightning. I've tried adding
the Cannon LBP5200 RPC server process to the exceptions list and this helps
with some applications, but unfortunately there's still a problem printing
from Office (Word & Excel etc.). The little blue donut spins for about 2
minutes.
Any suggestions on settings for the firewall?
--
Jan