After finally getting the errors out of my Iprint broker (thanks Peter!),
it seems to be running smoothly. Now for the next step: having some form
of access control so that only certain users can install the printer.

According to TID 10089134: When Printer Security Level on a Printer Agent
is at the default of medium, users will not be able to install the Printer
unless they are added to the Access Control List (ACL).

My printers are on medium security, but regardless of the fact if users
are member of the security groups that would give them access to the
printers, everybody can install a printer.

For Example: Printer A has Group 'Managers' as printer
manager, 'Operators' as printer operators and 'Finance' as users

User John is not a member of any of these groups, but if he goes to the
webpages and selects the printer he can install it anyway.

Any suggestions where to look? I would not like to work with a high
security setting as this would force authentication to everyody,
regardless wether they are member of the correct security groups or not.

We are using Netware 6.5 SP3, Iprint client 4.06.00