Socket in use problem

[BrianBut]

I have a newly registered site on pythonanywhere and followed your instructions. Having installed py4web and issuing the run command I get:
'''
Listening on http://127.0.0.1:8000/
Hit Ctrl-C to quit.
Socket 127.0.0.1:8000 in use by other process and it won't share.
Starting Rocket3 1.3.2
Listening on sockets: 127.0.0.1:8000
Listener started when not ready.
'''
I have checked everything I can think of. I don't know how to tell what it is using the socket. Any ideas?