You may encounter an issue where Exchange Server 2007 storage group transaction logs are not truncated after a successful backup. In our case Backup Exec 11d was the backup application being used. Backup Exec would report successful backups however the transaction logs were not truncating, leading to disk space problems.
The Application event log on the Exchange server had corresponding errors such as this:
Event Type: Error
Event Source: ESE
Event Category: ShadowCopy
Event ID: 2007
Time: 8:39:17 PM
Information Store (3408) Shadow copy instance 9 aborted.
The solution was to install hot fix 940349, which resolves some VSS snapshot issues. The hot fix requires a server restart.
Link: Availability of a Volume Shadow Copy Service (VSS) update rollup package for Windows Server 2003 to resolve some VSS snapshot issues