Ensure you don't have your IE9 in 'Compatibility View', as I found many of the BC templates are HTML5, which don't render in compatibility view.
If you switch it back to IE9 standard, it shows fine.
I found this out myself when I prepared a demo of BC for a client, then arrived on site to demonstrate and the site looked all-over the place.
Transpired client was a council that uses only IE8.
e.g. Looking at your demo, take a look at the <header> tag at the top. This is HTML5 code.
Hope this helps,
Should always have a good fallback for IE8 at the very least though and IE7 as the use stats of sites you will see sare still quite high.
HTML5Shim is the thing you will want to google for example
Side note, IE9 MS claim does CSS3 - but does not do it properly and a lot of CSS3 it does not do still as well
Nice one on HTML5Shim! Wish I'd seen that one before I ventured out to see my client.