Yup, that's what it was.  I was also missing return $block in hook_block().  Important stuff, I guess...

Thanks.

Steve

John Fiala wrote: 
On Tue, May 20, 2008 at 2:48 PM, Steve Edwards <killshot91@comcast.net> wrote:
  
I didn't get any bites on this one on the support list, so I'm hoping some
of you development gurus can help me.
    

You need to say 'return $form;' at the end of calculate_square_form(),
I'm afraid.