Group Policy Preference Extension - Printer Assignments causing slow login

I have a Windows 2008 domain with XP and W7 clients. I am using Group Policy Preference Extensions to assign network shared printers. The shared printers are on a Windows 2008 server running Print Management.

I use User Node Preferences and assign shared printers using Item targeting (typically NetBios computer names at the targeting item). When I do this, the time between entering your login name and getting to your desktop can be as long as 5 minutes. It seems as if the printer driver is being reinstalled every login. Is that possible?

Any ideas?

Thanks,

Dave