Tiger’s printing is relatively unlocked while Leopard locks printing. Therefore I imagine Tiger server has no way of managing it on a Leopard client.
Have you tried to relax the security on printer functions in cupsd.conf?
I have modified /private/etc/cups/cupsd.conf file to not require admin credentials when adding a printer. (my concern is that users not call a tech inorder to add a printer) I think in your case modifying this file could provide some relief.
Cheers
some more discussion here:http://lists.apple.com/archives/printing/2008/Feb/msg00053.html