the 'LDAP groups which allow automatic account creation' setting

We've been experimenting with the ldap groups module, using edirectory ldap server.

We seem to have it authenticating users and creating accounts as expected, however, as soon as we specify a group name in the "LDAP groups which allow automatic account creation" setting, and attempt to login with a user not of this group, the user can't login (expected), but if we look at the list of users in the database, the user account is still created.

Is this a bug, or am I doing something wrong.

I should add that, we've double tested this, by deleting the user out of drupal, and attempting to re-log in again, and the same thing happened.

I've also, tried logging in with a user that is part of the group that's in this "LDAP groups which allow automatic account creation" setting, and the user account is created as expected, and the user can login as expected.

Thanks!