Comment #1 on issue 493 by allber...@gmail.com: spawnPipe opens another instance of the applicatioon http://code.google.com/p/xmonad/issues/detail?id=493 This suggests that xmobar is not properly configured; you have xmonad.hs set up with DynamicLog, but xmobar is not listening for that data (and therefore won't know when xmonad is restarted, so it won't shut itself down). What does your ~/.xmobarrc look like? It should include a StdinReader *and* have %StdinReader% somewhere in the template; if you don't do both of those, it won't be reading its input and (a) it won't go away on restart (b) it won't show things like current workspace (c) xmonad will eventually hang (unless you are using GHC from git, or possibly the latest prerelease that came out something like 2 days ago).