The next thing that is supposed to come up, I think, is this:
Maybe whatever is providing that has an error and is causing this problem.
Are you using a stock theme, and if not, does changing it back to stock fix this error? My guess is this is something in the template file, or the config.
Are you using a different language file? (I’m guessing not, based on the blog.)
Or, is it possible not everything was uploaded properly? Some things I would expect to be in that directory are not present when accessed directly by URL. Can you confirm that a new bbPress 0.9.0.2 archive and your server have the same exact files?