printing over wide area net

I have a small problem that I can't resolve. I have a
wide area network (two sites) using Windows Server 2003
with 5 clients that access the server via Terminal Server.
I have a VPN connection between the two sites. Each site
has printer for that location also some of the printers
are shared over the WAN. A program is access from both
sites and we print from that program. The problem occurs
when we print from that program to the default printer
one time it will print on the default printer then the
next time it will print on a printer at the other
location. We have to go into print manager and reassigne
the default printer.

At site A we can print to a local default shared printer
with no problems, sometimes the next print job from the
program residing on the server will no longer go to the
default shared local printer it will go to a shared
printer at site B. Printer pooling is not enabled.

Any ideas?