When attempting to manage submitted jobs from within iManager (Manage Printer > Printer Control > Jobs) I'm presented with the error:

Exception reading Job List
Service Error: Unclassified server error
Service Other Error: FFFFFC6C
Service Other Error2: 0
Object Identification: .iprint01.iprint.printing.resources

This is true for a few randomly selected printers running on this manager, so I presume it may be the case for all. We have another NDPS manager running in the same tree on which jobs are visible, so it would appear that the problem is specific to the one manager.
Servers are running NW 6.5 SP 6 with latest Netware iPrint patches. Have tried looking at jobs using iManager 2.6 and 2.7.
Does anyone know what might be the cause of this?