Printing to a local USB printer on Windows 2000

I recently purchased a laptop with Vista Business pre-installed. I am able to
connect to a Windows 2000 desktop computer as long as the firewall is turned
off. So question #1 is: What exactly needs to be changed in the firewall (in
this case, Sunbelt Personal Firewall) on the Windows 2000 pc in order to
permit both discovery and sharing from the Windows Vista laptop to see and
communicate to the desktop with the firewall enabled? Question #2: The
Windows 2000 pc has a USB printer connected locally. I have installed the
Vista drivers for that printer on the laptop and I have provided the required
logon and permissions on the Win2K system. I then "connect" the printer in
Vista but when I attempt to print, although it appears that the print job is
being passed to the Windows 2000 system, nothing actually prints. I think
that the problem is likely on the 2000 system. Does anyone have a solution?
If the problem is a service or permission on one of the computers, maybe
someone could guide me in the right direction. HELP! I've already spent 3
full days on this problem.