[xmonad] remember layout(s)?

This must be a FAQ, but anyway ... As much as I like the tiling and mouseless behaviour of xmonad, the main obstacle in using it is that it does not seem to remember the layout of the applications when I log out (from KDE) and then log in again. There must be a way to achieve this? I know I can write preferred locations for apps in config files, but that's not what I want to do: it should remember exactly the previous layout. (Or at least which app was on which screen.) Best regards, J.W.