[xmonad] sending window to invisible workspace?

I have the following in xmonad.hs: myWorkspaces = ["0", "1", "2"] ... [((m .|. mod4Mask, key), screenWorkspace sc >>= flip whenJust (windows . f)) | (key, sc) <- zip [xK_y, xK_u, xK_i] [0..] , (f, m) <- [(W.shift, 0), (W.shift, shiftMask)]] now, I'm also using screenLayout, giving me two 'workspaces' on a single screen mod4-y & mod4-u work when I have two workspcaes visible, but mod4-i does not when I only have one workspace visbile, mod4-u and mod4-i both do not work is there some rule saying "you can only send windows to visible workspaces" ? thanks!