When I lock my Ubuntu 12.04 screen with Ctrl + Alt + L, the screen goes blank (as it should) and in 30 seconds, the login prompt is shown again.
Then "session expired" message is seen and it goes blank again. It repeats.
What should I do to fix this? (I just want it to stay blank until I move my mouse and press something on my keyboard)
I read here: that it may caused because of
VLC. But I did that fix, but it didn't help. Which other app might be causing this?