When opening the Windows Server Backup utility on a Windows 2008 server you receive an error that "the block level backup engine service has been disabled" when it is in fact running.
If you attempt to backup the server from a command prompt using wbadmin you receive an error that "the service cannot be started, either because it is disabled or because it has no enabled devices associated with it".
There are no worthwhile events logged in the System or Application logs.