The information below only applies to Network printers, not IP printers.
On the print server browse to the registry at:
HKLM\Software\Microsoft\Windows NT\CurrentVersion\Print\PrinterName
Check the Data of the 'Share Name' value.
If the value is blank then the client will not be able to set the printer as default.
To resolve this issue, reinstall the print driver on the print server.
Then verify that the 'Share Name' registry value is correct.
