After upgrading to Kubuntu 11.10, I'm no longer able to unlock my screen. The screen stays blank. Oddly, it seems I'm able to logout of my current session by hitting Ctrl-Alt-Delete Enter. Any advice?
I have a similar issue with 11.04 using the latest KDE. It would appear that the dialogue is somehow blocked by the screen saver. If you hit a button to invoke the login dialogue and type your password followed by enter the screen should unlock.