Hi everybody,
i had the same problem with hp lj 1320dn and 2055dn. It took me 5 years of my live to figuir it out why....
In our company we use HP Switches and HP Printers.
I have also disabled SNMP on our printserver, but didn't work.
The thing is: on our switches I have disabled SNMP authentication on particular port on which the printers are connected and enabled SNMP on the printserver.
AND yes it has worked.