Sometimes it throws up a "No New Content" message for me. But the header also says "Members" not "Forum." And I'm not clicking on the Members link, either. I've just assumed it's just a weird blip where I end up on a page where the content has not generated.
I reclick the "new content" link and it all comes in.
Just did it right now to make sure it was still going on. Yep. Did it again. Seems to happen when I'm not clicking directly on the "New Content" words. When I'm clicking too close to another link area.
If it's happening over and over again for you, then it probably is something like the cache, as Sakura said. But check and see if it's actually putting you in the "Forum" or if you're getting routed somewhere else. (Like "Members.") That's at least a place to start.