Having eZAutosave extension active while creating a first version of an object that includes a eZRecommendation attribute causes internal (fatal) errors everytime autosave operation is attempted.

steps to reproduce

• prepare a setup with eZRecommendation and eZAutosave (enabled by default)
  while tailing apache's error log and with firebug console errors tab opened,
• create a first version of an object that includes the recommendation attribute
• enter some value on fields and switch focus (triggering the autosave operation to execute)
  watch the errors both in the error console and in the apache's log