Samba Unauthenticted Printing

I am running a Samba 2.2.8 server for access from XP workstations.
It's been working fine, but some users wanted to be able to print to
the shared printers even if they had not logged in. So, I changed a
few things including the global setting:

map to guest = Bad Password

This enables a user to connect to the server as guest whenever their
password or username are wrong, so they can always browse guest
accessible resources.

But, it creates a problem when a user logs in locally to a workstation
with a username which is the same as a username on the server, but the
passwords are different. Once the workstation has connected to the
server as guest (which it evidently does automatically because the
username or password are wrong), it will not connect as any other
user, even a valid one. They get the error: "Multiple connections to
a server or shared resource by the same user, using more than one user
name, are not allowed. Disconnect all previous connections to the
server or shared resource and try again.". Of course, issuing a 'net
use' command from the command prompt indicated that there are no
"previous" connections anyway.

The entry could be changed to:

map to guest = Bad User

But this would only allow access from users already logged into the
workstation with the correct (same as the server) username and
password, or users logged into the workstation with a username that
does not exist on the server. Other users (those logged into the
workstation with a username that matches the server and a password
that does not) would have no access to the server until they logged in
using the correct password. Thus, they still can not print until they
log in.

Does anyone know a way to allow access from a valid user, who has
differing local and server passwords but who has not logged into the
server? (Besides setting up a separate print server)

Thanks four your help.