Get Data from XML file

I need get data from http://feeds.idealist.org/xml/yourCause.xml. Every time the code skipped the yellow highlighted part and went to "catch" section. I had tried to remove "&",  still have no lucky.

It works fine with another link http://www.allforgood.org/api/volopps?output=rss&key=yourcause.  

try

                {

                    XmlDocument doc = new XmlDocument();

                    rdr = new XmlTextReader("http://feeds.idealist.org/xml/yourCause.xml");

                    if (rdr == null)

                    {

                        return projects;

                    }

                    doc.Load(rdr);

                    XmlNodeList listAll = doc.SelectNodes("//VolunteerOpportunities/VolunteerOpportunity");

                                                if (listAll != null)

                  {

                       // Do Something

                  }

            }

catch (Exception)

                {

                                        return null;

                }

                finally

                {

                    if (rdr != null)

                    {

                        rdr.Close();

                    }

}