With 3.2 GA ?
Also make sure your web browser cache isn't the issue (empty the cache or try a different browser).
Also the content of the iframe is different in both picture, are you sure the exo.product.developing parameter is guilty ?
Notice that with Dexo.product.developing=true, you also need to re-start server after changing to get effect.
BTW, could you provide more details what you changed in stylesheet.css ? ( like what are changed and which CSS files ).