I have an MX3100 in an environment with Win2k3 server and Vista and Mac clients.
They are using account codes.
The printer is shared through the Win2K3 server.

All printer dialogs are excessively slow - up to 3 minutes to open.

Haven't tested with XP client yet.

Im wondering about the server load in that mixed enviroment, IT will sometimes tweak the print spooler request to a lower priority so that file and application services don't suffer from too much lag. I would connect my laptop directly to the network port on the machine, and show that customer that there is no delay at the machine. Then I would configure one of the workstations to print directly to the machine's IP, should be as easy as creating and IP port on the workstation in Add Printer wizard, provided you have admin privledges on the workstation. Then if the driver GUI comes up normally you will know it is a server issue.

Jeff - I've already done that - direct printing dialog is fine. This is a very under-utilized server - it's really just simple file sharing and we were testing it with nothing else on the network - laptop, switch, server and mfp.