SQL Server 2008 R2 Drops Connections when Anti-Virus Scan is running
I see that you are still running SQL Server 2008 R2 SP1, so I would suggest that you update your software.  If you update to SQL Server 2008 R2 SP2 CU 2 there is a fix for this problem.  

You can read about this particular problem at: http://support.microsoft.com/kb/2491214

I would recommend not applying the "workaround" but just getting up-to-date with SP2 CU2 (at least).  You should know that SP2 CU8 is available.