[knc1]

If you know that there is a possibility of non-ascii characters, then why use cat?
Isn't that like aiming at your foot and pulling the trigger to see if the gun is loaded?
I.E: Not your best idea of all time.

Have you tried to telnet in and re-start the shell that you have cat'd to death?

PS: You have your cause and effect reversed: "Broken ssh gives a broken pipe" is the order, although that might not be what you have seen at the remote end.