Using Wireshark I can see that the miner is receiving the response "401 UNAUTHORIZED" after sending the post with the credentials. The web page returns a "Sorry, I don't know you" with the 401 Unauthorized.
I've created a Worker in the proxy who connects to three pools (and of course enabled XD)
http://img221.imageshack.us/img221/3126/dibujosbb.th.jpgNot posible to connect with the worker credentials nor admin credentials with miner.
Is there any way to login with worker credentials inside the web page using a Web Browser? It's all http protocol and I shuold get some JSON response if I understand.