Comment #40 on issue 177 by donvodka: xmonad does not follow ICCCM and ignores WM_TAKE_FOCUS protocol http://code.google.com/p/xmonad/issues/detail?id=177 I believe this patch has a bug that is only visible after several hours of having a java application opened and working with it (e.g. netbeans), read on please. Sometimes when running java under *patched* xmonad, after working for a while (3 hours or so) with a java application (say, netbeans) I find other applications (especially firefox) to be very slow at gaining focus, e.g. if I switch from the java workspace to the firefox one, it'll take about a second or so to give focus to the firefox instance. If I close the java application then everything gets back to normal. It gets worst as time goes by, until the java application is closed. Has anyone experienced a similar behavior? What can I do to troubleshoot this? if I run "top" I see X taking a lot of cpu when changing between WS. Any help will be appreciated.