Non workflow driven holds not able to hold lines from progressing if line status Awaiting Fulfillmen

A little background -

We upgraded from 11.5.10 to R12.1.3 in Nov 2012.  Since the upgrade we have had some instances where a hold has been placed on an intangible item that is part of a configured line and although the hold applies successfully it does not actually keep the line from progressing.  We use workflow drive holds and open holds, this is only occuring on the open holds.  The issue only occurs if  the line is already in 'Awaiting Fulfillment'.  We are a high tech company that sells hardware, software, and services.  Often times we will hold the Service line, but allow the