I have a Winforms application and I use EntLib to connect to a SQL Server 2005 DB. The application is working ok, but sometimes, and lately more often, we have started receiving this error from the db when opening the connection:

A connection was successfully established with the server, but then an error occurred during the login process. (provider: Shared Memory Provider, error: 0 - No process is on the other end of the pipe.) (Microsoft SQL Server, Error: 233)

The problem is intermittent. The user works well for a couple of hours and then suddenly the exception is thrown. Sometimes it happens when we run a small process that loads a file and then inserts the data to the db.