Garbage Collection and CTA Orphan File Deletes - space not reclaimed?

Hi all,

We have a full EMC Storage Suite and we have decided to implement Orphan File Deletes using our CTA to reclaim space on our Centera Pool.  I ran the CTA Stub Scanner followed by Orphan File Deletes and saw a saving of over 120Gb (in the Policy run output) on the CIF I ran it against.

I waited for Garbage Collection to run and could see that the Sweep Space Reclaimed was over this amount showing 286Gb.  When I checked the Pool Capacity, Files etc they were all MORE as we had archiving running over the weekend and the amount of increase totals the files that were archived over the last few days.

I thought that with Orphan File Deletes, the files would be deleted from the Centera after the monthly Garbage Collection runs?  I don't see a saving of the 120Gb anywhere.  Does the Centera have some sort of retention policy on it to keep the files for so long following the Garbage Collection? 

Can anyone help?

Cheers, Donna