funny guy...
are you sure that "hostname" is a valid login-domain and "testuser" a valid user in the login-domain?
try using real users and it will work just fine :)
Comment on Re: Win32::Perms - Can't use Add or Allow methods
hostname\testuser is not what I am really using but substituted information, where "hostname" is the name of the computer, and "testuser" is the name of a regular user.