There's actually another tip you can choose if you don't want uninstall McAfee altogether...
This is one suggestion...
http://www.gnutellaforums.com/genera...-solution.html
If no luck there...
http://www.gnutellaforums.com/258193-post45.html
These are the Port Forward instructions for your router...
Port Forwarding for the Linksys WRT54G
And one more tip make sure you are using Java 6...