Cannot eject CD after browsing stored images in gthumb

After browsing photos stored on a CD with gthumb it is not possible to eject the
CD afterwards.

1. Insert a CD with images on
2. Open gthumb and open the folder /cdrom/
3. View an image
4. Close gthumb
5. Try to eject the CD via the CD Desktop applet or 'eject' command line.
Expected result : CD ejects.
Actual result: An error message is given
"Unable to eject media :
umount: /media/cdrom0: device is busy
eject: unmount of `/dev/hdc' failed"

To eject one has to find which process is using the CD and kill it.
$ lsof | grep cdrom
gam_serve 8912 rich 61r DIR 22,0 2048 4224
/media/cdrom0
$ kill 8192
$ eject
$

But gthumb should probably release its lock on the cdrom when you close the program.
Problem exists in Ubuntu Linux 5.04 : The Hoary Hedgehog release.