DVD/CD won't eject

[The Jeep]

Hi-

I've just bought an OEM Pioneer DVR-111 DVD drive.

When I push the ejecty button on the front of the unit, the drive doesn't open, but when I go into 'My Computer' and click on the drive icon, then it ejects.

Is there some simple setting somewhere that needs to be made, or could this be caused by a faulty drive unit? I've updated the firmware, but still the same result. Does seem odd, as if something's over-riding it...

Cheers, Jeep.