Are both of you new customers? While this kind of thing shouldn't happen, sometimes things don't work completley right. What this error means, basically, is that Apache isn't fully configured the way it should be. You can find more information about the error here.
The best thing to do is to submit a support ticket through the web control panel. Simply complaining about it on these forums probably won't help, as these forums are customer to customer.
The site you mentioned in your post works for me. Maybe support fixed it, or the system caught up with itself.