Did you check in Catalog–>Manage Products–>(select a product)–>Design if you’ve selected a Page Layout? You must do this because the default is “No layout updates”. And you have to do this for all products, but you can try Guillermo’s suggestion to update all at once. It’s Magento, so this is the way it’s done.
You have to do this for CMS pages, too, as I see you haven’t done that yet. Go to CMS–>Pages–>(select your home page)–>Design and then select “homepage” as your layout. This is done because Magento offers such flexible functionality to run multiple stores in multiple languages with multiple templates at different times. For example, you could have a Christmas template in English for the US and have a Hanukkah template in Hebrew for Israel in the same store while offering the default template in Chinese just from Nov. to Jan.!