I could be way off-base here (it wouldn't be the first time!), but:
It could also be that your browser thinks it's smarter than you are. I've seen browsers apparently redirect themselves (without any redirect having been set up) to variations on a URL, and/or to whatever is set as
their default search engine, but so far as I know, that usually only happens if the browser can't resolve the URL as entered, or if the user didn't explicitly type the protocol prefix on the URL.
Does it happen with other browsers? Does it happen if you try it from someplace with a completely different web connection? Have you tried explicitly typing the
http:// or the
https:// at the beginning of the URL?