Active Directory problem

Hi, I am testing out Active Directory integration on an iMac today. I have followed your instructions as per "AD integration in 3 hours or less", but if I try and login at the login screen with the name of someone in AD, it pauses for a couple of seconds, then the screen goes black and says... Darwin/BSD (Administrators-Computer.local) (console) login: What does this mean!!? I am a bit lost now! I am also not clear on the section on mappings. Any advice?