Version: (using KDE 4.3.0) OS: Linux Installed from: Unlisted Binary Package Sometimes, when a window is closed the taskbar keep on showing the task as it hasn't been closed, but minimized. Obviously when the task is clicked to maximize the window, nothing is shown. As I've said it only happens sometimes, not always. The only difference between the default configuration and the one I use is that I only show the tasks of the current desktop. I don't know exactly in which conditions it happens, so feel free to ask for information you may need.
*** This bug has been marked as a duplicate of bug 203032 ***