RSS feed not working

When I go to mypage.com/feed, i get my feed page and can subscribe to it,

however when I add the rss widget to my sidebar and enter my feed url http://mypage.com/feed I get

Error: could not find an RSS or ATOM feed at that URL.

and the rss icon does not show on my sidebar, anyone know how to rectify this?

Regards,
Leggy