This is already discussed in the German sub-forum:

I have the problem that under KDE symbols disappear. That can be symbols in the task-bar, the start-up menu, within kmail as well as within non-KDE programs like a missing home-icon in firefox. It is an absolutely random behavior, which icons disappear. Only the symbols are missing, if I click on the position , where it should be, the full functionality is given. I'm using openSuSE 12.1 in the tumbleweed version on a Samsung netbook N130. Did anyone experience the same or does anyone have an idea whats the reason for this behavior?