Version:            (using KDE 4.3.2)
OS:                Linux
Installed from:    Debian testing/unstable Packages

Sometimes it happens that task manager does not stop to show a window after it's closed. I think this possibly only happens with grouping.

For example, I've had multiple instances of a pdf reader open, and after I've closed them all, it sometimes still happens that one of the entries for the (now closed) windows appears in the task manager. It is also shown on all virtual desktops, not only the original one, even if I have configured task manager to only show windows on current desktop.

Left-clicking on that task manager entry does nothing. Right-clicking on it brings up the usual context menu, but e.g. choosing Close does nothing. The entry simply sits there, taking space from task manager, until I restart KDE. ps output from terminal confirms that the application itself whose window it was is no longer running. However choosing Move or Resize switches to the virtual desktop where the window was when closed; Minimize, Maximize or Shade don't do anything.

Architecture is 64-bit Debian testing/unstable (x86_64).