Linux and Windows can't share files on SanDisk MP3 Player

I have a SanDisk Sansa m200 MP3 Player, and I can load both data and music on it from both Windows XP and Fedora 4. However, when I put a file on the player from Linux, I can't see it in Windows and vice versa (even MP3 files).
What do I do?

Thanks a lot!

I was having the same problem here... After a bit of searching through sandisk's support pages, I came up with the solution: just put your Player on MSC mode before plugging it to your PC. With your player turned on, go to menu, settings, USB and change from auto detect to MSC. Plug it in, and windows will finally be able to see all your files! Haven't tested this on linux yet, though.

MSC is a standard that works on Linux, Windows and Mac OSs. Only use MTP when you sync with windows computers. You can read more here: http://thesansa.com/forum/index.php