I have the same issue. I am using the amd catalyst 13.11-beta. It happens when i resize, minimize, or bring forward. Does not seem to happen when i maximize the Konsole window. It does not happen all the time, but more often then not.
Konsole version 2.11.3 KDE version 4.11.3 catalyst 13.11-beta V1 AMD 6950 video card. I am also using dual monitors, if that makes any difference and will happily provide any additional information required. Thank you for making Debian a great distro. Patrick |