Ok, so DNS is ruled out.

Second that comes to mind (in my experience):
If my application uses WYSIWIG text-editors or anything that tries to
read printer-information, I experienced a huge startuptime if the
default printer was one that was added to the active-directory.

If I changed the default-printer to a local attached device or at least
one that was assigned to a local port, startuptime decreased dramatically.

So.... does your application need to read printer-capabilities, and if
so, is the queried printer one from the Active Directory?

regards,
John