I signed up for an account. On the NIT I am seeing what I expected to see, tadalists is deciding that the browser it's what it expects and is not stylizing the page the way you expect. It is not sending down a rss feed in it's place.

Rather than do a test for functionality, they are using agent sniffing to change the style and features of the html page. This is considered bad form by some and can only be truly fixed on their end. You can try setting the useragent on the NIT to a something more like FF3 to see if it "just works".