Print Jobs Take Forever (Vista to Vista, on a Domain, 2 Network Printers)

Hi,

I'm having a bit of trouble with a recent addition to my network.

One of the three PC's in a location (all running Vista Business) has
two USB printers attached to it, which are shared with permissions to
everyone.

When the other two machines send print jobs to these devices, it's hit
or miss. Sometimes they will print, other times they will take hours
or even DAYS to spool and print.

Originally, these machines were on just a local workgroup and
experienced the same issues, but now they are now connected to a
Domain Controller (Server 2003 Standard) at another location via a VPN
setup to be part of the company network, and still experience the same
issues.

I've checked the event logs on the 2 client machines, and have found
an error that Microsoft does not have a record of on their site:

"the print spooler failed to reopen an existing printer connection
because it could not read the configuration information form the
registry key S-1-5-18\Printers\Connections"

So far I've tried the following:

-Disabled TCP Autotuning
-Disabled TCP/IP v6
-Disabled Sleep Modes
-Manually published the printers to AD
-Disabled UAC on the client machines

I haven't had much luck yet figuring out the issue, right now, one of
the printers has a print job from Oct 10th "printing" with no
results. There are documents queued up until today pending still.

Does anybody have any ideas here? I would not think it would be a
driver issue since they are both different make/model printers,
although it is a possibility. Could there be a missing registry key?
or a print spooling issue?

Any help, comments or suggestions are welcome.

Thanks for your time and help

-James

As a quick update, if I look in the registry under the specified
key...there is no "Connections" key under the -18 key, but there is
under the others.