Google Analytics question

Hello everyone,

If you’re using GA for your items, you saw (I think) one thing. When you trying to see the referral path for landing pages, all you can see is (not set) in field. I.e: if user found your theme in ‘blog’ category ( url: http://themeforest.net/category/wordpress/blog-magazine ) and clicked on your item, in GA you’ll see that someone visit your item. But you can’t see the referral path (i.e. this url: http://themeforest.net/category/wordpress/blog-magazine ).

Any tips? Ideas?