Sorry for the late answer, we have been rather busy lately with a project.
We are not sure what was causing your issue. We have connected to your server ( http://weblabduino.pucsp.br
) and we seem to be able to login fine with "admin"/"password". Have you managed to solve the problem?
If you haven't, we were thinking that you could try either of the following:
a) Checking what the response to the HTTP request is through the browser debugger (through the Developer Tools in chrome, or FireBug in Firefox, or similar) so that we can see the clear-text response (The TCPFlow would normally be enough, but the particular request seems to be compressed).
b) Using Apache instead of the Python "built-in" server. Maybe then the problem would solve itself.
Tell us how it goes, or if you have any other issue / question!