I am using Umbraco 6.1.5 and this happens on the production database only.

I get the same node appearing twice on the content tree (same node Id) one of which appears unpublished with a star and the other being published.

The problem is in the database, the cmsDocument table cotnains multiple rows of the same node, both of which is published (published = true) but only one of them has newest. 

I have created a script that identifies the nodes

  SELECT * FROM cmsDocument

  WHERE NODEID IN (SELECT nodeId FROM cmsdocument 

  WHERE Published = 1

  GROUP BY nodeId, published

  Having count(published) > 1)

  AND PUBLISHED = 1 AND NEWEST = 0

I have already over 60 nodes that are corrupt this way. I have a script that fixes the problem but more importantly I need to know what is causing it.

I suspect courier might have something to do with it.because the development database and QA database don't have this problem. 

Any ideas are very much appreciated.