I'm not sure how to get those back... but I just added a radio station from Live365.com.
1) Go to Live365.com
2) Look down at the bottom... for "Listening Settings".
3) For MP3 Player, you'll under the Web Player, "Additional Options". Choose from them, "MP3 Desktop Player".
4) Save your settings, and then search for a radio station.
5) Choose one and start it playing... it will let you download a file ... generally something like play.pls. Save this file on your desktop or wherever.
6) Open the file with gedit or look at it in a terminal. You'll see a long url that looks something like:
7) Just grab the http://.... part after the File1= and copy it.
8) In Banshee while looking at your stations, click the Add Station icon up top by the volume icon. Fill out the bits you want and put that long URL in for Stream URL. Save. Enjoy.
In general this should work for any Online Radio station. You just need a way to access the stream URL.