I have the same problem. My proxy runs on default port and is not in transparent mode. I use "authorize and filter" mode (though "always accept" doesn't work either). I didn't change anything in the firewall, so I can see the "usercorner" service running fine as a firewall rule.
It seems there's a problem with squid because when I try loading the user corner page on a browser set to use a proxy, the page page doesn't load. AND, if I use a browser without proxy configured it loads the page normally.