I installed Jaguar (10.2.6) on my iPod today so I could use it to image multiple machines, and after doing so, I discovered that I could not listen to any of the files I had purchased from Audible.com. I simply plugged in the iPod and re-copied them from iTunes and all is well again. I have no idea what exactly causes this, but I thought I'd share it just in case anybody who happens to be an Audible.com subscriber has plans to turn their iPod into a mobile utility drive.
[robg adds: I haven't heard this before, but thought it was worth a heads-up...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030806215731210