[DESKTOP] Idle lock screen does not require password

view story

http://www.kubuntuforums.net – I am aware this is a known KDE bug however i cannot seem to find any workarounds with google or through searching these forums. If i remain idle for 15min and the lock screen comes up, all i have to do is move my mouse or press a button and the lock screen goes away without any password input! Locking the screen due to other reasons works however (manually locking it or resuming after suspend). Could anyone point me to a way to fix this? (HowTos)