Ughh... I'm sorry, I meant m4a not mp4. I checked the file operations menu, and m4a is listed there, but it still will not add m4a files to a playlist. And I have the CCC Pack installed. Is that good enuff, or do I have to specifically install the K-Lite codec pack? And I got a i7 processor. Which uLilith should I be using? Thanks again for all your help!!