CD eject won't work: "unable to eject, last error: Invalid argument"

[Colin Brace]

Every so often Fedora stops letting me eject CDs:

$ eject /dev/cdrom
$ eject: unable to eject, last error: Invalid argument

Why does this happen? I've seen both on my desktop as well as my laptop, 
and I saw it under FC3 and well as FC4. Nothing seems to solve it except 
straightening out a paperclip and ejecting the disk manually and 
rebooting. As far as HCI design goes, it is a worthless error message.