Have you tried manually ejecting the DVD? there should be a tiny little hole on the front of the DVD bay, use a pin or something and push it into the hole, it should eject the Tray.
I am also thinking that it would also be the DVD that you are using, i'm thinking that it might not be compatible with the DVD drive.
So it would spin up but when you want to eject it, you will recieve all sorts of grief.
Also have you tried ejecting the disk once the computer is shutting down? Or when you very first turn it on, try to eject it when your at the Bios screen or something..

just a few thoughts.

cheers
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