Printing after upgrade NT 4.0 to Win2K

After recently ugprading a print server from Windows NT 4.0 to Windows 2000, I begain experiencing difficulties printing to HP LaserJet 4si, 5si, and 8100N printers. Large documents from specializing applications including TIFs from Windows Imagingwill spool and begin printing, but will often restart printing and never complete. This worked prior to the upgrade and printing from Microsoft’s Word 2002 and other Office applications appears to function properly. Any advise?

Thanks!
Brad