Problem with Gem on Windoze

Last night trying to install Rails on Windoze I ran into the dread:
ERROR: While executing gem ... (Gem::RemoteFetcher::FetchError)
getaddrinfo: no address associated with hostname.(SocketError)
This seems to be fairly common, with no solution. It turns out (after hacking remote_fetcher.rb) that HTTP_PROXY was set in the environment (the day job), unset it and everything works fine.

You gotta love a language that comes with sources, programmer heal thyself :-)