Today i changed my wordpress theme and after that my RSS feed stop working.Sometimes feedburner works for few moments and after i get again a error. I reinstalled wordpress,deactivated and reactivated plugins..nothing.. Look what error i get: In IE: The XML page cannot be displayed Cannot view XML input using style sheet. Please correct the error and then click the Refresh button, or try again later. XML document must have a top level element. Error processing resource 'http://niceblogger.com/feed/'. I Firefox: XML Parsing Error: no element found Location: http://feeds.feedburner.com/nblogger Line Number 1, Column 1: Please tell me what to do..
Feedburner has a reset option in there somewhere. Give that a try. While the actual feed from your site is valid, it does have some errors. Try the reset first and lets see where things are in the morning.