Trouble shooting TCP An existing connection was forcibly closed by the remote host

Hi,

I am receiving multiple errors like the ones below from a 3rd party application that connects to an SQL database, the application support this to be cause by a 'network issue', however I am having trouble detecting any faults out side the applications.

*Unhandled Exception: A transport-level error has occurred when sending the request to the server. (provider: TCP Provider, error: 0 - An existing connection was forcibly closed by the remote host.)

A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The specified network name is no longer available.)*

SQL logs show no errors at all, pings test between the server and client have issues even while these errors are occurring, TCP chimney is disabled.

Database server also hosts two other SQL databases that are accessed by other client applications and appear to have no issues.

I have been running captures between the DB server and then clients and hopping to find some indication of why the connection is being broken (such as indications of faulty hardware) so far no luck.

What should I be looking for or am I wasting my time ?