Using 7.19.5, it is not possible to use NTLM and do a POST against a server like IIS7.
1. Request w/ content length but no body! <== bad libcurl! must send body or 0 content length
2. Response 401 authorization required
3. Request (NTLM authorized) w/ content length + body
4. Response 400 bad request
IIS correctly tells libcurl to go away with its authorized request because it didn't finish sending the body from the first request.
I discovered this while trying to do what I would expect is a very common scenario -- use libcurl (via Axis2/C) to send a SOAP request to a web service.