CRM 7.1.l to MAS 2013 PU5. Occasionally getting sync error when accepting SO Order or SO Quote, not every time. However, Order or Quote save fine, no errors in CRM Activity Log in MAS or System Logs in CRM. Can immediately go to CRM & see Quote/Order on the Oppo, can fire up the screens back to MAS. We don't have to reset anything for the sync to work the next time; Integration Engine is working fine. Can't reproduce on demand. No other network connections appear dropped or giving errors. Seems to start in the afternoon & once it happens, it continues for rest of day on some orders. Error attached.