libssh2 iOS Error 31

I have tried several projects based on libssh2 for iOS and I consistently get error -31 when trying to upload files. The file is created on the server, but no data is uploaded. I suspect that it maybe that something is unsupported on the server as -31 is defined as LIBSSH2_ERROR_SFTP_PROTOCOL. I only have access to the server via sftp and I cannot get in touch with the admins. I can do sftp from the command line on my mac. My code is based on NMSSH. However, I have tried the demo app on DLSFTPClient with the same result.

Anyone else have a similar problem. If so, how did you correct it?