You are definitely viewing a cached page. The reason I say this is that the page you are describing doesn't even exist on the server, it was removed on March 4th and replaced with a new page that is white and has big ugly letters on it that says the forum has moved and to update your bookmarks. It contains a link to the new forum, and a redirect script to forward you over. So there is nothing we can edit, if it isn't even there. Unfortunately, a lot of people aren't getting it due to their cache.
Sometimes a cache can be very difficult to clear. I've gone through that myself, on many occasions.
However, it could also be cached by your internet provider. I recently learned that some internet providers have a way of caching information to reduce their bandwidth. This is only a possibility for people behind a proxy, from what I can tell. How long it lasts will depend on the isp and when they clear their cache
