Version: (using KDE 4.2.2) OS: Linux Installed from: Debian testing/unstable Packages After wakeup from sleep mode, the unlock screen shows up. Its background is not solid black as I'd expect, but is quite random: sometimes it shows corrupt stuff, sometimes it shows parts of the display I had before the computer was changed to sleep mode. I'm using Xorg server v1.6.1, "intel" driver.
Sounds like a driver issue. In fact, a known issue and mentioned all over kubuntu's stuff: http://www.kubuntu.org/news/9.04-release Which has some workarounds for X. And probably means that the bug has been reported to Intel.