I have a 30GB Creative Zen MP3 player, and while I love the little bit of kit Creative have fucked up a lot of it. They issued a firmware update a while ago that actually makes the PC stop recognising it as a Zen, and so you can't transfer tracks on to it, off of it, whatever. Creative's response to this? Post a page on their site - nowhere near the no-warning unmarked firmware update that is still there - saying to simply transfer tracks using WMP instead. Which, by the by, doesn't work.
Thank Christ for the latest version of Winamp and its plays-for-sure (hah!) compatibility.