On Thu, 4 Dec 2008, Neil Wilson wrote:

> Using the debugger I've traced the problem down to libssh2_session_startup,
> which is returning LIBSSH2_ERROR_KEX_FAILURE. Why it is doing this I don't
> know.

Then I suggest you switch over to building a plain sftp test app using
non-blocking sockets directly with libssh2 and see if that works to figure out
if the problem is within libcurl or in libssh2... The libssh2 package comes
with a few sample apps that should be fine.

I'll also recommend you use a recent libssh2 version off their CVS or daily
snapshot as some bugs have been fixed since the latest release.

-- 
  / daniel.haxx.se