[xmonad] Can avoidStruts stop working?

Does anybody else run XMonad on Arch Linux AMD64 (non-testing)? Since about a week (and a half) ago something seems to have caused avoidStruts to be ignored, because xmobar is covered by any window I open. I've tried unsuccessfully with my full config and the recently suggested new sample config here on the list[1]. Any idea what's happening? It's possibly an operator issue, but I don't know how to debug it. [1] https://mail.haskell.org/pipermail/xmonad/2015-December/014977.html