@linuxnoob, Could you open up a terminal from your menu (X Terminal) and type the following into it:
Then if the screen goes black after you enter the lock code press Ctrl+Backspace, go back to the terminal and press Ctrl+C to close applock. Then Scroll to the top of the terminal and check if there are any error messages there. Otherwise you can do this instead:
and attach the applocklog.txt file to your next post so that I can look at it.

Thanks