This request operation sent to net.pipe://localhost/Microsoft/Dynamics/GP/eConnect/EntityOperations did not receive a reply within the configured timeout (00:01:00). The time allotted to this operation may have been a portion of a longer timeout. This may be because the service is still processing the operation or because the service was unable to send a reply message. Please consider increasing the operation timeout (by casting the channel/proxy to IContextChannel and setting the OperationTimeout property) and ensure that the service is able to connect to the client.
Standing orders from the boss (sigh) <smiles>
"Blog every error that you get"
So, here goes: I was adding a company to an existing client and got the error above. eConnect did a 30 second timeout and returned this message.