Exchange Agent incremental backups only backup the transaction logs so that a point-in-time recovery of the database can be made.  (Restore the full backup, then restore the incremental to replay the transaction logs.)

Granular restores of a single user mailbox should be selected from the full backup.

Thanks guys, the backups are definitely going to disk and I am sure I have preformed a granular restored from incremental backups before.  Sazz, I am curios what you mean by the backups should be in a policy as I am not familiar with that terminology within backup exec?  Can you explain a little more?

Yvied please read the ADMIN GUIDE 12.5 page 275

■ The full job templates and incremental job templates must be part of a policy.

That is probably the issue, they are not on the same volume due to space issues.  I will see if that helps and repost.

we have to create a policy and 2 templates in it. One for full backup and one for incremental. In the job setup you will find the option on the left side to create policies.
Please check http://support.veritas.com/docs/342311

Sazz is correct, so I pointed all his posts. 

If you do not have the exchange backups as part of a policy, then the restore option on Incr backups will only show the log files.  So if your exchange job is not part of a policy, then you are clearing logs every night, but the only backup you can restore from is the full.

Setup a policy, get the templates working, and the jobs should be fine.  I had issues getting my policy setup at first after noticing I could not do a restore from my Incr backups.  I ended up calling into Symantec and a tech helped me out as I was having a stupid issue on my side that was completely me missing something.

Short answer, create a policy, then you can restore from Incr backups.