Where's my free space gone on my MP3 player? I have a Sansa Fuze MP3 player, it's 4 GB.

I plug it in my Mac I have a capacity of 3,7 GB of which apparently 1,8 GB is in use.

Problem is I only have arround 120 MB of MP3s on it...

Who's stealing my free space ?

Here are DiskInventoryX screenshots. I have the same results with du and the terminal.
It might also be the trash -- I'm not sure how DiskInventoryX copes with trash directories on external drives. It might be worth emptying your trash while the drive is mounted.