Creating a Child Group

I have followed the instructions to the letter and my sub (child) forum has the slug: http://artistsspot.com/groups/stephanies-stainedglass-gallery/forum/. See how it ends in /forum/. I get the following error when clicking on that link: Sorry, we can't find the content you're looking for at this URL. Please try selecting a menu item from above or to the side of this message to get where you'd like to go. That slug is good though, what could I be possibly doing wrong?