[xmonad] Is this layout (with Tall) allowed?

This is my configuration file. Are parameters to Tall acceptable, as well as the double use of a single layout? (It builds and is usable, but sometimes things go wrong, like xmonad saying the focus is on firefox but everything I type going to emacs. Before trying to understand why, I would like to know if this configuration is supposed to work.) I'm using xmonad as it comes in latest Ubuntu. Thanks for your thoughts, Maurício ---------------- import XMonad import XMonad.Layout.Grid main = xmonad $ defaultConfig {borderWidth=11, modMask=mod4Mask, normalBorderColor="#00ff00", focusFollowsMouse=False, layoutHook =((Tall 0 (1/100) (1/2)) ||| (Tall 1 (1/100) (9/10)))} ----------------