On kde 4.9.2. Laptop with intel graphics, and ubuntu precise. Kde packages updated to 4.9.2 via the kubuntu ppa. Intel graphic drivers updated to latest mesa via oibaf ppa. After a suspend+resume or anyway a screen lock+unlock, the unlock screen dialog remains (inactive) over all the other windows and cannot be erased. Restarting kwin is the only way to get rid of it. Reproducible: Sometimes Steps to Reproduce: 1. Suspend the laptop. Resume. See that the screen is locked. 2. Unlock it by entering your password in the unlock dialog 3. See the screensaver stopping and the desktop appearing Actual Results: At times, the unlock dialog remains on screen, over all the other windows. It is completely inactive. It cannot be clicked, moved, filled in, erased, etc. Typing kwin --replace on a terminal makes it disappear. Expected Results: After the unlock, the unlock dialog always disappears.
suspend / resume the compositor (shift+alt+f12) will do as well *** This bug has been marked as a duplicate of bug 306186 ***