Sidebar not working in shop

I am trying to setup an new site and have a sub-site for a shop using WooCommerce. As you can see from this link http://bkashop.expressyourselfmusic.co.uk/?post_type=product The sidebar appears at the bottom of the page and not along side the products. This only happens in the "Shop" page - other pages are fine eg http://bkashop.expressyourselfmusic.co.uk/?page_id=5 When I switch to another theme the sidebar is fine but I really want to use your theme. Please help. Thanks