Have been setting up HP network printers for quite sometime on SCO open server 3, 5.04 - 5.07. Purchased a new HP 1320n. It has JetDirect Built in. After configuring the Jet Direct, I Try to run the SCO HP Network Software trying to send PostScript or the HP-GL/2 file, they will not print. The printer access fails. I configured a diffrent printer (HP1220) with an external HP 500X Print server using the same IP, Gateway config. and it works fine. Anybody see this ??? What is diffrent ?? 
is the network speed on the internal print server the same as the network speed on the switch? when properly setup, you should be able to telnet to any of the hp network printers ... the inability to do so generally means a network issue which in this case is most likely a network card speed issue ... good luck!
I figured it out. After doing research on the SCO web site, the problem seemed to point to a SNMP config problem. The newer HP printer servers have much more detail in the configuration of SNMP. It is not just a easy enable for SNMP. There is a place in the configration of the print server that states " Default Get Cmnty " Enable/Disable. The SNMP was enabled but the Default Get Community was not. Once I enabled the Default Get Community, it started working. The internal and external print servers had two very diffrent setups dealing with the SNMP configuration. Sometimes it's the simple things that send us into a panic. And by the way I talked to HP and they were no help.