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If it would help, I can give you a test account on my own server. 

Thanks very much for the quick response!  I'm using the free version of their SSH server.  FYI, both Goodreader and Textastic use the same SSH library according to my server logs:

  <parameters clientVersion="SSH-2.0-libssh2_1.1"/>

I tried setting "Connections" to 1 but I still got the "Error in the SSH layer."