Hello Nikos, It is so late, that I can't write one sentence correct. So let me try again: - Linux Client only uses one TCP connection for POSTing username and password. - Windows Client uses two TCP connections for POSTing username and password. The current code requires that both username and password are sent in one TCP connection, if that is not the case it looses the state, if it looses the state it doesn't know the username anylonger and than the authentication fails. I think there are multiple solutions: - Save the state on the server - Set a cookie on the client - Change the code so that username and password are transmitted at the same time. Cheers, Thomas