Bug: Lower than Administrator can't post when set to registered members only

Not sure if it's my set up, usually is, or the plugin but if you try and comment as a user with level lower than administrator the comment doesn't appear on the blog or in the comments area to moderate. It does however store the comment, as if you change the privacy level to something such as blocking search engines they all appear. It can take 10-15 minutes for the email to come through and comment to show after changing privacy settings though.