Version:           unspecified (using KDE 4.7.0) 
OS:                Linux

When using KDE for couple of hours sometimes appear „ghost” windows. Free space with size of normal elements near other elements. I don't know how to reproduce this or if this is a specific application that causes this problem. I've fresh installation of KDE from meta-packages. These „ghost” elements are sometimes between other elements, sometimes at start (don't know if in the end of elements list, because it's invisible (if it's on start then I can see that something is wrong, because all elements are moved right).

I'm Using 64bit Arch.

Reproducible: Sometimes

Steps to Reproduce:
Just using KDE.

Actual Results:  
From time to time appear a new „ghost” element. Today I've got two!

Expected Results:  
There should be only real elements.

When I try to r‐click on this free space, I get only Plasma panel options, no kind of specific window options, so I can't check if there should be concrete element.