(In reply to comment #19)
> Only dri2.c:934 make DRI2CanFlip return FALSE.

That's while awesomenauts is running fullscreen? So can_flip() also returns
FALSE in that case, contrary to comment #7?

Apart from backing store, possible reasons I can think of for the window pixmap
not being the screen pixmap are:

* A compositing manager is running, which doesn't unredirect fullscreen
windows.
  This includes things like xcompmgr -a, which doesn't involve any special
  effects like shadows or translucency.
* The awesomenauts window is redirected automatically, e.g. because it uses a
  visual which is incompatible with the root window visual.