This is happening since 10.5.3 to me and 10.5.4 didn't fix it: The active windows flashes quickly into inactive window mode and jumps back on active again even though i didn't touch any other windows and didn't switch to other apps at all. In 10.5.3 it only happened with safari. Now it's happening with almost every app. Sooooooo damn annoying! Anyone else with that annoyance?