Same problem here. Sansa Clip identifies tracks / albums / artists with special characters (grave acute accent, umlaut, cedilla, circumflex, etc.) as ‘unknown’. The tracks lose their numbering, but seem to play without problem. Also, the special characters are displayed correctly on the Clip.
I’m using the latest firmware - V02.01.32F.
I’m using J.River Media Center to manage my music and transfer to the Clip. It does not offer conversion from UTF encoding to ASCII.
Is there another solution?
Are SanDisk going to fix this? It must be effecting thousands of their customers.