UPDATE: forget about manual install from any attached version from AulaWiki page. I0've just deleted it from there as attachement, since I got it working from the http://edu.tikiwiki.org/mods repository. See my other post above
Moreover, the sql commands from before were missing the workspaces_assistant being assigned. I've added that back to svn (and to that copy on edu.tw.o mods repository) a couple of hours ago.