Exchange online backup encounter different files during verification

are you using the Exchange server option installed with Backup Exec or are you just running backup exec?

as a footnote you did buy the OFO option didnt you? (Open file option)

If this is the error you are getting "0xa00084ca - The data being read from the media is inconsistent." then unless you have OFO and the exchange option then this is normal behavior :(

and

34113 - Backup Exec Alert: Job Failed
(Server: "NAME") (Job: "JOB") JOB -- The job failed with the following error: The data being read from the media is inconsistent.

When performing a VERITAS Backup Exec (tm) Agent for Microsoft Exchange 2003 differential/incremental backup after a full backup performed with Microsoft Volume Shadow Copy Services, the job fails with "Incremental and differential backups are not possible because one or more of the Microsoft Exchange transaction log files has been deleted."
TechNote ID: 263514  

http://seer.support.veritas.com/docs/263514.htm

backupexec exchange agent is used and OFO is not. NOT getting "0xa00084ca , only error from backupexec in event viewer --a format inconsistency was encountered during tape reading operation.

give me the event ID it will probably start 576something ?

57612. By the way, exchange 2k is running in this case, not exchange 2003.