Running cl-http under mac osx

I have downloaded the last version of cl-http (cl-http-70-159-devo).

It seems that the only way to have cl-http running under MacOs X (10.2.4) is
to set the port to something else than 80 (let's say 8080).

This is the error I get:

Error in process HTTP Listener (80): UNAUTHORIZED-CLIENT-ACCESS:
Unauthorized client access. Permission denied.

I also get the following error on the proxy start up:

Error in process HTTP Listener (8000): OPENTRANSPORT-ERROR: Generic
OpenTransport error.  Address already in use.


Any suggestions on how to configure OSX or cl-http to get rid of these
errors ?

Thanks

Bruno