After applying a version of Store.exe that is later than 06.05.7651.26 on a computer that is running Microsoft Exchange Server 2003, the Exchange databases may fail to mount if the security descriptor of the database object has been modified to include a well-known user or group and more than one domain exists in the forest. This problem can also occur if a security identifier (SID) in the database object has conflicting values with another object in Active Directory directory service.

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Microsoft, Exchange Server 2003, KB 930241, Update