So far we used ZCM to push printer policies to the workstations and that uses the ZCM credentials to install printer drivers (I suppose).
But if I upgrade the printer drivers on the iPrint server (From HP Universal Driver V5.1 to HP Universal Driver V5.7) users are asked for admin credentials.

How do I prevent that from happening? I thought the printerdrivers should be upgraded using the iPrint software, not via user rights?
I have set "AllowUserPrinters = 3" in iprint.ini, but to no avail.