Can any one resolve this???

Lets say there are 2 seperate networks, network A and network B, each with their own network printers that work on their own networks. What if a workstation was connected to both networks, but somehow the workstation cannot print directly any documents opened/taken from Network A on network B's printers.

Why? Is there a network printer compatibility problem between different OS's if the 2 networks are running different OS's. Namely win2k and winxp. Could firewalls be involved and how?