When I use my iPod as an external harddisk and drop folders into it, it shows up in the iPod file window as two identical folders (one is not called "copy"). If I delete one of these, they both disappear. Changing one changes the other. So, it is only a "cosmetic" issue, but it's still kinda annoying.
Edit: I'm using a G4 PowerBook and a 15GB 2003 iPod. Any advice (aside from getting a new iPod) ?