Version: 4.3.0 (using KDE 4.3.0) OS: Linux Installed from: Unlisted Binary Package This is easy to reproduce (names are guessed by traslanting from italian): - right click on the task bar, and enter settings; - select "Show only applications on active desktop"; - open an application on a desktop; - switch to another desktop: now the task bar should be empty; - press Ctrl+F8 (or trigger Desktop grid effect). You should notice that all panels have empty task bar, even the in the desktops with open apps. On the contrary if you have open windows in the actual desktop you'll get the same list on the other panels.
Created attachment 36142 [details] Screenshot of Desktop grid effect with empty panels. As you can see 3 out of 4 desktops have an open app. But if you trigger the effect from the empty one you get an empty task bar on all the panels.
*** This bug has been marked as a duplicate of bug 158120 ***