Hi, I'm not sure if this is the right place to ask because the problem may lay in my Apache or system configuration. I use the Apache proxy module to forward a HTTP request from port 80 to a Happstack application listening on port 8000 via `ProxyPass / http://localhost:8000/' on Windows XP. When calling http://my_domain in the browser, I get `503 service temporarily unavailable' and in the apache logs `proxy: HTTP: attempt to connect to 127.0.0.1:8000 (localhost) failed'. So I tried to access http://127.0.0.1:8000 manually in the browser but got a connection error, while http://[::1]:8000/ works perfectly and displays the content returned from the Happstack application. Maybe I'm wrong, but isn't the problem here that Happstack only accepts IPv6 addresses, while Apache forwards an IPv4 request? Best wishes, Maciej