[Zope] not showing any views...

When I try logging into http://url:8080/manage it shows the view of index_html in the main frame instead of the management area. If I try clicking on any other folders, besides Quickstart and Control_Panel, nothing happens--the view of index_html just remains in the main frame. I have tried logging out and logging back in with every user, but I get the same result. I've also tried stopping and restarting the zope server. Any ideas why this is happening, or how I can correct it? Thanks