Check your MySQL Server's configuration file (my.cfg, usually) that the server IP is set to '0.0.0.0' (accept from all addresses) and not '127.0.0.1', the latter of which is the default. If set to '127.0.0.1,' the server will only accept connections from localhost.
If the file indicates the local IP, change it to '0.0.0.0' and restart the server.
