when saving a playlist with relative path in the same folder as the mp3s are, the playlist isn´t copatible to windows.
e.g.:

/mnt/wind/music/testfolder
playlist.m3u
file1.mp3
file2.mp3
....

the m3u saved by amarok:
../../../mnt/win_d/munic/testfolder/file1.mp3
../../../mnt/win_d/munic/testfolder/file2.mp3
...

m3u should look like this:
file1.mp3
file2.mp3
...

I think nearly all windows player save playlists (relative paths) without any path when playlist is in same folder as the mp3s are.