The following code generates a 401 => Net::HTTPUnauthorized error.
From the log:
response-header: x-powered-by => ASP.NET
response-header: content
Mechanize 2 supports NTLM auth:
m = Mechanize.new
m.agent.username = 'user'
m.agent.password = 'password'
m.agent.domain = 'addomain'
agent.add_auth('http://server', 'username', 'password', nil, 'domain.name')
http://mechanize.rubyforge.org/Mechanize.html
tested: