Catalog failing with 160 then retrying and succeeding

I have a catalog backup that will fail with code 160, retry, and the complete.  This doesn't happen every day, it's more like every other day.  The job does run everyday.  

I have split the services up between 2 different service accounts to make sure it wasn't a windows single sign on error.  I also have the DR file being stored in a different volume than the main catalog file.  Both volumes have the everyone permission applied to them.  At this point I'm at a loss as to why it fails every other day.