Some days ago power was accidentially removed from my server running zimbra 5.0.2. After this the statistics graphs in the administration interface have gone flat-line. The daily mail sent by /opt/zimbra/libexec/zmdailyreport also just returns "No messages found". I don't see any errors anywhere obvious and everything else seems to work fine. I've tried running the cron commands that check the databases etc. manually and they don't find anything wrong.
Does anyone have a clue as to what can be causing this?