The archive might not list the file, but it's there. Every week, I open my Windows Media Player, go to "open URL" and just change the date from last week. For instance, this is what my WMP has in it's memory
http://sportsnoteradio.com/archives/Sportsnote_tues_102406.mp3
All you have to do is change it to _110706.mp3, and bob's your uncle.