In attempting to set the screensaver to lock after 'x' number of seconds, setting idle-delay and locking the value, that value is ignored. Unlocking the value enables the screensaver after the duration of idle-delay.

Under certain situations this can also cause the screen to blank out and appear locked, but mouse/keyboard activity results in returning straight to the desktop and not to the unlock dialog (even with /org/gnome/desktop/screesaver/lock-delay set to 0)

Environment:
 - Ubuntu 12.04.2 LTS (precise)
 - gnome-screensaver v3.4.1

Steps to reproduce:
1. Lock the value of /org/gnome/desktop/session/idle-delay by setuping up dconf as outlined at https://live.gnome.org/dconf/SystemAdministrators, specifically

$ mkdir -p /etc/dconf/profile
$ mkdir -p /etc/dconf/db/local.d
$ mkdir -p /etc/dconf/db/site.d/locks

$ cat /etc/dconf/profiles/user
user-db:user
system-db:local
system-db:site

$ cat /etc/dconf/db/site.d/screensaver
[org/gnome/desktop/session]
idle-delay=10

$ cat /etc/dconf/db/site.d/locks/screensaver
/org/gnome/desktop/session/idle-delay

2. Run `dconf update` to updates these changes.

3. Verify that /org/gnome/desktop/session/idle-delay is locked (`dconf watch /` and then attempt to modify the value.)

4. Notice that after 10 seconds the screensaver does not activate nor does the screen begin to fade (indicating that it will soon lock).

5. Remove both `screensaver` files created above and update dconf again.

6. Manually set /org/gnome/desktop/session/idle-delay to 10 seconds.

7. Observe that after 10 seconds the screensaver appears.