I found another solution for this problem here. It looks simpler than the other ones suggested here and it worked for me 🙂
I’m having the exact same problem. I am new to wordpress but i think i’m doing it right. I tried adding different feeds (tumblr, my other blog, etc.) but although everything looks fine on the widget page they don’t show up on the website. Help!
http://www.rosapomar.net/blog/
