title: Magento - updating catalog.xml
body: <p>I'm trying to update a magento theme (the theme name is blank_seo), and i'm trying to change the product page default template to 3 columns. I've tried updating the app/design/frontend/default/blank_seo/layout/catalog.xml file. but so far nothing is working. 
  The only solution that i've found is manually changing the 'Page Layout' dropbox to 3 columns. If anyone has a simpler/quicker way of doing this (or a reason why my editing of catalog.xml doesn't work), I'd be extremely thankful!</p>