I've got a problem that's driving me nuts!

I can't get my Beta 2 (public) version of Vista to print to my network
printer.

There's two XP machines and a Win2000 machine already on the network that
happily print to that printer.
I have shared files on the network the Vista installation can "see"  and
edit all shared files.
All other computers on the network can "see" and edit the files I've shared
on the Vista installation.
So I KNOW there's network connectivity and permissions.

I try to add the network printer to my Vista installation  using a valid
ADMINISTRATOR account on all 4 machines.
I also find the new printer driver in the Vista directory and install it.
When I try to print, all I get back is "Access denied"

I've explored the firewall settings ( with little knowledge) and they seem
to be O.K.

PLEASE What am I doing wrong???

Thanks

DonW