NPR MP3's not recognized

I wish I could help, but maybe it’s helping to chime in and say I’m having the same problem? I download mp3 files from NPR, drag them to my “News & Talk” playlist, and synchronize to my Clip Zip. I’ve done this for years with my old Sansa YP-7J, no problem. This is a brand new Clip Zip to replace it. Windows Media player says it synchronizes. If I browse the player’s internal memory in Windows Explorer I see the files there. If I double click on the playlist in WMP it opens to show all my files listed. But if I go to the playlist in the player’s own menu, it says [Empty]. This is very annoying. If there’s no fix, I’ll have to return it. The thing is, I HAVE had this work, sometimes, even with the new player. I’m not sure what has changed. Did NPR recently change something in their format?