Event ID 3079 soruce MSExchangeIS Public
Unexpected replication thread error 0x80040219 on database "First Storage Group\Public Folder Store (SERVER)".
EcReplFolderMessagesUnpack EcReplMessageUnpack FReplRcvAgent
AV in the way? http://support.microsoft.com/?id=305145
http://support.microsoft.com/?kbid=301234
Is your db pub1.edb corrupt?
http://support.microsoft.com/kb/313184
Moving from Exchange 2003 to 2007? Make sure you have your ducks in a row (some items go away in 2007!)