I have an MPIO player, and I just tried mounting it with my Slackware, but to no avail. There should be a way to get it; I'll mess with it for a while. I'm kinda worried though, because even Windows XP didn't see it as a "USB storage device" - you have to use it's proprietary software to load songs on it. So if anyone has an idea, that would be great!
(I have the fs type as "auto" in my /etc/fstab for USB)