It's a browser issue. Browsers need to know what protocol to use when contacting a site.
Your browser (probably every browser) will guess "http" when there's no port number included in the URL.
But when a nonstandard port number is included in the URL the browser can't reasonably guess which protocol it should try, so it doesn't.
Talk to the people who wrote your browser; perhaps they'll be willing to change this behavior.
(But I'd be willing to bet not.)
Jeff