Strange problem:
I have seven users and two groups on the system. I have tried to add other user and it doesn't work fine. The user cannot entry to system, but it says that the user don't exist, but I can see on the list after of press button "show all users". Then I have tried delete him and the system says the same thing: "the users don't exist", after I list all users and I cannot see him already.
Thanks in advance!!