So it seems like indicator-appmenu wasn't catching xerrors properly, hence badwindow errors were propagating to mutter which wanted to bail at the first sign of trouble (wimp!). The linked branch of indicator-appmenu should make a significant difference to the stability of Unity.
So it seems like indicator-appmenu wasn't catching xerrors properly, hence badwindow errors were propagating to mutter which wanted to bail at the first sign of trouble (wimp!). The linked branch of indicator-appmenu should make a significant difference to the stability of Unity.