Looking for VB.NET Help with TCP Communications

[Bob Schroeck]

Is anyone on the board familiar enough with .NET-based network communications to help me with a problem?  I've got a situation where I'm sending a string to a program on a different computer using a TCPClient, with a TCPListener active and waiting for a response.  The response should be all but instantaneous, and when detected would spawn a new TCPClient to accept the connection and receive the response, but instead I'm timing out.  I can see that my message to the remote computer is being received and acted upon, and the return message is being generated (and logged).  I can't change the remote program, as it's a standard configuration for multiple products.  And the code I'm using is allegedly the standard implementation for the other side of the connection.  But regardless of whether I leave the code as it was already written, or attempt to tweak it, I see no evidence that anything's coming back across the network at me.

Ideas, suggestions, brickbats?

Thanks.
-- Bob
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Then the horns kicked in...
...and my shoes began to squeak.