I normally talk about SharePoint topics but this post is also important for non-SharePoint people. First let me explain what is the relationship between impersonation and SharePoint, or better, the relationship between SharePoint and the thread [security...

This problem was fixed in KB961175 . The patch will keep the problem from happening again in new lists/libraries you create after applying the patch. However if you have a backup before the patch the restored contents will continue to show the same error...