Why can't I lock, log off, or switch user after Ctrl + Alt + Del?

[Windows Central Question]

Cannot lock, log off, or switch user after "Ctrl" + "Alt" + "Del"

I have joined the computer to a Small Business Server 2011 and I cannot log off of the network, activate the lock screen, or even switch users. Even after restarting the computer I am not required to input my domain password. Seems like a big security issue. Has anyone experienced similar problems?