keypress events in multi-page Shoes apps

[Sarah Nordstrom]

I'm trying to use the keypress event in a URL-based (multi-page, in 
theory) Shoes app, but I can't get it working.  Given that I'm new to 
Shoes, it seems likely this is my fault.  The code below seems like it 
should work to me, what am I doing wrong (if anything)?  Making it non-URL 
based and putting the keypress event handler inside the Shoes.app block 
works fine, but once I subclass Shoes and make it use URLs, it stops 
working.
Any help appreciated. :)

 - Sarah
---

class TestShoes < Shoes
  url '/', :index

  def index
    keypress do |key|
      alert(key.inspect)
    end
  end
end

Shoes.app