A customer runs Sage 300 v 2012 on SQL.  Starting this morning, they have been getting the dreaded 49153 error, intermittently.  Happens on all workstations (3).  But other applications that use SQL (Accellos, for instance) are running with no problem.  

And it is only from the workstations, running Sage 300 from the server presents no issues.  The users are able to access Accellos from these same workstations.  They can access Accellos even when they get the 49153 error.  So the connection to the server seems to be working ok.

It isn't a system idle condition - they can be in the middle of a Sage 300 transaction when the server becomes unavailable.  Luckily, they were able to get all of the AP checks printed today (!) but the database error reappeared within a couple of minutes after it completed.

The IT folks have not made any changes in the last day.  There have not been any changes to Sage 300.  The data volumes for receiving via Accellos are slightly elevated but not above previous loads.

I would suspect an infrastructure issue if all applications became equally unresponsive, but that is not the case.

Any idea where we need to look for a resolution?