I’ve decided to compare one of the working playlist files and the “empty” Amarok generated playlist. Two things were noticeable:

1. Amarok uses forward slashes, like in a Linux environment, and the working playlist used backward slashes.
2. The working playlist used relative paths without any prefix – directly beginning with the path. Amarok prefixed the relative paths with a dot-slash (./).

After noticing those things I’ve modified my Amarok generated playlist to look like the Windows generated one, and voila, it worked. I tried going through Amarok’s configuration dialogs to find some option controlling the format of generated m3u playlists, but couldn’t find any (I’m using Amarok 1.4.10). So with my newly found wits I’ve looked for a way to make using the playlists easier. I’ve came up with the following one-liner:

find -name "*.m3u" | xargs -I{} sed "s/^\.\///;s/\//\\\\/g" -i'' {}

The command should be run in the MUSIC directory of the Sansa Clip’s filesystem. It recursivey looks for m3u playlists and for each one strips any leading dot-slash and replaces forward slashes with backward ones. It can be used to easily convert all your playlists to the format understandable by Sansa Clip.