Websocket Server with Python and Tornado. Always "Connection Closed"

Websocket Server with Python and Tornado. Always "Connection Closed"

I've tried to create a Websocket-Server with Python and Tornado in the
same steps as you can see in this tutorial:
http://mbed.org/cookbook/Websockets-Server
The Server is running and I can see acitvations in the shell. But the main
problem is, that I only get the message "connection closed" when I open
the HelloWorld.html. The same message i can see in the server log and the
websocket handshake is not running. I do not understand the problem and
need help.
The OS is Ubuntu and webserver is Apache2.
many thanks!
Chris