[xmonad] Per-monitor EWMH Gaps

Hi all, Is it possible to have per-monitor (Xinerama) gaps defined? Either I've an errant program defining EWMH hints, or I'm doing something wrong, but I've got taskbars and what have you which set the appropriate EWMH dock hints, starting on monitor 1. But for monitor2, I end up toggling the gaps manually. Is there a way of doing this properly? Note also this solution falls over if I end up switching workspace 1 on monitor 1, to monitor 2. David