OK.

I found the reason.

I'm using SecureCRT to connect through serial to the empeg. Even though I clicked RTS/CTS hardware flow control OFF, my existing connection re-did the setting back as I exited 'properties-mode' and 'disconnected'.

Sorry My bad. You might want to emphasize this in the FAQ once more. Now it works wonders. Thanks for all the help everyone. Especially the note about characters echoing back helped me trace back the problem.