Version: (using KDE 4.4.1) OS: Linux Installed from: Ubuntu Packages Under System Settings->Window Behavior->Window Behavior->Advanced, uncheck "Hide utility windows for inactive applications". Open two windows, group them, then close the active one. Now, the other window stops getting any events. You cannot click it or move it; mouse events just go to the window below it. It does not get repainted, either.
hmm, looks like the minimize state gets borked the window is not marked minimized, yet unmapped - what you see is just the "shadow" in the comositor which, assuming it's not minimized, still paints the unmapped window which, being unmapped, does of course not update (into redirection)
*** Bug 238716 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 225500 ***