User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:13.0) Gecko/20100101 Firefox/13.0 Build ID: 20120508180640 Steps to reproduce: Often developers run a local web server in address+port locahost:X Actual results: When you type in this address like http://localhost:8080 and the server is down you are taken to www.localhost.com:8080 Expected results: localhost is a special hostname. People accessing localhost as directly typed address never have the use case where they should go to www.localhost.com. Thus, auto-completion behavior of www. and .com messes up developer workflow: If possible Firefox should report normal "server down" error instead, as for developers the server is often simply crashed.