I've put a bunch of music on my shuffle via rhythmbox, verified that the shuffle
would play it by ejecting and playing it.  Then I wanted to clear the music off,
so in rhythmbox I selected all the music on the shuffle and told it to move the
music to trash (my only delete option).  All the music "went away" according to
rhythmbox, and the shuffle itself gives the flashing lights as if there were no
music on it, however the used disk space doesn't change and I'd quickly be
unable to put new music on the device even though it thinks there is none.