In Exchange 2003 running on Windows 2003, when using NTBackup (aka "Backup Utility for Windows"), you won't be able to back up the system state at the same time as the information store, due to a change in the interaction between NTBackup on Windows 2003 and Exchange 2003:

http://support.microsoft.com/?id=820852 explains it:

The Backup utility activates all Volume Shadow Copy service backup writers, including the backup writer used for Exchange Server 2003. By doing so, Exchange Server 2003 is in a "backup in progress" state even though Exchange Server 2003 is not selected as a component of the volume shadow copy backup. The Backup utility does not release Exchange Server 2003 from "backup in progress" state until the backup operation is completed.

The Backup utility does not use the Volume Shadow Copy service to back up the Exchange Server 2003 information store. The Backup utility uses the Exchange Server 2003 online backup streaming API to back up the Exchange Server 2003 information store. Because the Volume Shadow Copy service has already locked the Exchange Server 2003 information store for backup, the streaming API cannot bind to the databases. As a result, you experience the symptoms described in the "Symptoms" section of this article.

Note: Volume Shadow Copy is a new feature in Windows 2003 (that Exchange 2003 supports) that allows backups to happen while the Exchange information stores are open. For previous versions of Exchange, some vendors have products that do "hot split snapshot backups"; see KB #311898 for more information about the support policy for those types of products. For more general information about backing up Exchange, see KB #296788.