Feedburner feeds not bieng accepted?

I am trying to add the following and the results i get follow:

1. http://feeds.feedburner.com/zenhabits
2. http://feedproxy.google.com/thesimple...
3. http://feedproxy.google.com/getrichsl...
4. http://feeds.feedburner.com/economist...

1. Added as a keyword box - nothing shows up.
2 & 3. &4 do not add at all if a previous feedburner/feedproxy feed has been added.

I get the feed preview in all these cases but after i click the green arrow, the feeds refuse to go the right pane.

whats going on?