So I got one of these this Christmas, and want to add cover art to my MP3 library so it will display on-screen during playback. It seems simple, but I'm having some issues. In short, MP3 files created with cover images in Musicmatch seem to work. But existing files I add an image to with a tagging utility do not display the image on the Archos player.

I'm sure many here have in-depth knowledge of all things ID3v2. Any advice would be appreciated.