Unanswered problems in twitterfeed

When I test the RSS feed I get the message: "The URL is not valid and cannot be loaded".
The URL is http://libros.soybits.com/atom/ and it parses ok in feed readers. Same thing with a second url, http://libros.soybits.com/rss/
Any ideas?

I used to be able to log on via Yahoo (when I had to select to grant access). I cannot now do this and so I have a load of twitterfeeds setup but cannot access to edit. How do I get to these?

Twitterfeed shows a 410 authentication error from Twitter, yet when I go to setup and test the authentication it checks out OK. Our Twitter page hasn't updated in more than a week because of this. Password is all lowercase alphanumeric.

I'm not sure if my twitterfeed is working. I posted a new article last night but it still hasn't shown up on twitter. The url for my feed is http://www.thatcoolbroad.com/feed. My twitter username is thatcoolbroad.

Thanks for your help!
tcb

I need to stop my twitterfeed. It's causing problems. How do I delete or stop?