I managed to find the solution (see below). For the benefit of others, I also make a summary of what should be done to use succesfully .M3U playlists with the Sansa Clip when you just drag and drop it instead of using the “synchronization” feature of iTune or Windows Media Player:
(Assuming that you use Mp3tag to create the playlist)
1- Into the Sansa Clip, go to Settings/Usb mode, check “MSC”.
2- I think that you’ll have to format the player, then copy again your mp3 into the player
3- Open Mp3tag
4- Go to Options/Export
5- Create a new export configuration and name it “M3U8 Playlist, relative file paths”
6- Then double-click it and paste into it the below text:
$filename(m3u8,utf-8)#EXTM3U
$loop(%_counter%)#EXTINF:%_length_seconds%,%artist% - %title%
%_filename_rel%
$loopend()
7- You can create this 2nd export configuration if you want, if never a new firmware requires absolute path (?). Name it : “M3U8 Playlist, absolute file paths”.
$filename(m3u8,utf-8)#EXTM3U
$loop(%_counter%)#EXTINF:%_length_seconds%,%artist% - %title%
%_path%
$loopend()
8- Uncheck “Write BOM”
9-Change the directory for the one where your mp3 are
10- Select the mp3 of your playlists
11- Richt-click, choose “Export…”
12- Select “M3U8 Playlist, relative file paths”
13- This create a file with the “.m3u8” extension. This is your playlist.
14- Put it into the Music folder of your Sansa Clip, AND NOT into the Playlists folder (as strange and illogical as it could appears).
