[xmonad] First keystroke is lost

Hi After restarting X , I have a problem that I already had some time ago, but I can not remember if/how I resolved it ( as far as I remember, a similar issue has been discussed in the forum , but I can not remember that neither) The problem is, after switching to another window ( console ) , the first keystroke is always lost , although the cursor shows that the window has already the focus. Can anybody help Thanks a lot Peter