Printing in Windows XP

We recently upgraded our workstations to Windows XP but our servers are Windows NT. Now the users are having printing problems with HP 4000 series network printers. It seems they have lost the ability to print in landscape, even the preview won’t turn to landscape, and to print watermarks. We have tried uninstalling drivers and reinstalling them. We have tried using the 4100 drivers. Does anyone know why this would occur and/or how to fix it?