Lock screen behaviour

Dear community,

I am on a laptop with 11.2 and KDE4.3 installed. Since recently, my “lock screen”-function is behaving in a weird way. If I lock the screen (or screen is locked by screen saver) and want to unlock it again, the system asks for a password twice. The first time, I need to enter the correct password. For the second time, I can enter anything and the screen gets unlocked (if I used the right password the first time).

Where can I disable this strange second password query (I do need the “lock screen” function though)?

Thanks a lot in advance,