Well I cannot check - the DBAs will have to.  I was surprises as the SAME Data Source used by the other data sets which would be accessing the same schema - using procedures.   The obvious was permissions, yes.  Thought maybe somehow the SQL Text vs Procedure was part of the problem but I suspect its is as obvious as it appears.  The DBA(s) maybe only have granted Exec on report procedures - and not granted SELECT on dbo.   Its an inherited solution from 2009.  I'll shift it upstream and not waste my time on it.

Thanks guys.  Sometimes the obvious is the best answer