Scratch pool assigning more tapes than necessary

Hello!

I would like to preface this by warning that I am a novice concerning Netbackup, and am doing my best to learn. I appreciate any help/information on this issue.

I have recently configured a scratch pool because I was occasionally getting 96 errors on a specific policy, and was told by a support representative that a best practice is to let the Scratch pool assign tapes rather than manually assigning them.

I have a seperate policy that has written a slightly less than 6TB in the current week. This amount of data is typically stored on 3 tapes per week. However, since creating the Scratch pool, 7 tapes are assigned to this policy this week, meaning that 4 have been allocated from the Scratch pool.

I read this article on how tapes are assigned: http://www.symantec.com/business/support/index?page=content&id=HOWTO32854

I'm thinking maybe some of the volumes are at the end of media state, perhaps. Or, after reading this tech article http://goo.gl/x8qHRh, that maybe NetBackup is trying to store entire jobs on one tape rather than conserve space.

Do either of these seem plausible? Why is the scratch pool allocating so many tapes for this policy?

Thanks,

Chris