the xlockmore build needs to have an entry in /etc/pam.d to function correctly. As is, when you use it to lock the X screen, you cant enter your password to unlock the screen, since it cant autheticate (via pam) correctly. a '/etc/pam.d/xlock' is missing. For my own system this seemed to be sufficient for /etc/pam.d/xlock: #%PAM-1.0 auth required /lib/security/pam_stack.so service=system-auth