eject: unable to eject, last error: Invalid argument

[Matt Patterson]

When I try to eject a CD using either the right click option, or typing 
into the command line, I am only able to get the cd to come out if I use 
sudo. If I dont use sudo, I get:

eject: unable to eject, last error: Invalid argument

and the cd doesnt come out. If I use sudo, the same error appears, but 
the cd does come out.

I am a member of the cdrom group.

Any idea how to make this work properly?

Matt