KDE4 Lock screen freeze

I am having some problems with the KDE4 lockscreen

Sometimes after residing in locked session I cannot log back in.
The input is frozen and the mouse is gone. The indicator is blinking in the password field on the middle screen of 3.

I try to press just about any button. I’m able though to go to a plain old console with Ctrl+Alt+Fn
A few minutes later the lock screen just comes to life for no apparent reason.

I am using the kernel 4.7.5 and the default distribution KDE4 in OpenSUSE 13.2.

I’m thinking I should just upgrade to Leap 42.2, but I had so much work to get Bumblebee working that I have postponed it until I really have to. Perhaps I will make the jump to Leap 42.2 later this year.

Edit: Wrong forum. Could a moderator move this over to Applications?

I have a similar problem. Only keyboard does not work. It is annoying.