After weeks of our customers disatisfaction, and after the latest windows updates, our team managed to find a working solution to the problem:
- On the computer that shares the printer (call it server), activate the administrator account, and secure it with a password.
- On the client computers, add the credentials of the server's administrator account.
- Restart everything
- Map the shared printers on the client computers.
Hope this helps, was september, now its cristmass...