AccountManagement create user return 'object already exists' exception

Question

I'm trying to create a new UserPrincipal in a specific OU inside ActiveDirectory, and it returns an Exception with the message 'Object already exists'. (obviously) The user don't exists in that OU, and I'm testing its existence.

What am I doing wrong?

Here's the code throwing the exception:

public UserPrincipal CreateUser(string username, string pass,
        string givenName, string surname) {
    PrincipalContext context = this.principalContext;
    UserPrincipal user = new UserPrincipal(context);
    user.SamAccountName = username;
    user.UserPrincipalName = username;
    user.GivenName = givenName;
    user.Surname = surname;
    user.SetPassword(pass);
    user.Save();
    return user;
}

Edit 1: After unit tests, I found that the code is ok. I use this method in a lib (where I run the tests), that is called by another application, which has an Windows authentication mode enabled. Maybe the app is sending that authentication to AD?

Answer 1

sAMAccountName must be unique across the enterprise. You mention 'specific OU' when creating the user. Is it possible you have another user with the same username/sAMAccountName in a different OU?