So, the long and short of it is that I want to add a printer given at the following URI:

http://192.168.0.4:631/printers/Officejet-3600-series

This printer is hosted by Ubuntu.

On my vista machine, I go to Control Panel -> Printers -> Add a Printer -> Add a network [blah blah] -> The printer that I want isn't listed.

On this screen, I choose "Select a shared printer by name" and enter in the above URI.

When I click "Next" it pops up an error message saying:
"Windows cannot connect to the printer. Make sure that you have typed the name correctly and that the printer is connected to network."

Any tips? Funny thing is, I was able to connect to this printer from my Mom's laptop with no issues, which is also running vista. Not sure what's up there. Also, as expected, I am able to connect to the printer from my Ubuntu laptop with no issues.

The printer is an HP J3680 All-in-one.