At the bottom of the "Listen again" windows is a help button, have you pressed that?
Under "What software do I need " it says
Q.Why won't the new 'Listen Now' player work on my PC - the old one used to work fine?
A.Our new 'Listen Again' player launches in a new window and pulls in information from several different servers. If you have Norton Anti-virus or Firewall software installed on your computer, you may experience some difficulties loading our player properly. If you have trouble accessing the player, please contact your Firewall support centre for help.