Wrong icons in task manager

Using openSuse 13.1 all updates applied.
An X-Windows application with multiple windows, each with different icons in the title bar, displays the standard X-11-Icon in the task manager, irrespective of the used icons in the window. In KDE 3, these icons are displayed correctly.

kwin --replace does not help!

Please advice how to fix.

As far as I know, resolving this issue involves rebuilding the icon cache. But I don’t know how to do that. Sorry couldn’t be of much help.
Maybe other community mates can help you out.
You can also look in the KDE forums for the solution.