XP Vista Network Printer Share Problem

I just added a vista ultimate sp1 machine to my existing network. All other
computers are xp pro sp2. One of my xp computers has a HP 4215 pfs attached
via usb with a share. Initially, I was able to print to this printer from my
vista machine, but over the weekend, the printer disappeared from my printers
folder. When I go to the add a printer wizard, the wizard finds the shared HP
printer. I then select it and hit next. A window pops up and reads, "Windows
can not connect to the printer The specified port is unknown".

The share still works on all my xp machines. I deleted and reinstalled the
printer on the machine that it is cabled to. I tried to restore back to a
point where I'm pretty sure the printer was working. I'm at a loss of what to
do next. Any help would be appreciated.