Hi chrisf2,
Backup Exec System Recovery 7.0.2 (fully patched with LiveUpdate) should not have any issues with creating a successful and uncorrupted backup of an Exchange 2003 SP2 on Windows Server 2003 SP2. Make sure that Windows and Exchange are also fully patched and updated.
VSS should quiesce the Exchange Database properly. You can create a Stop and Start batch file for the Exchange services. Then use the .bat files thru the Backup Job to stop / start the Exchange services.