Yes, it shows, but the "Erase" button is not available. If this helps, here are the data given by the Disk Utility (sorry; it's in French...):
PIONEER DVD-RW DVR-112D :
Révision du programme interne: BC14
Gestion de la gravure: Oui (lecteur livré par Apple)
Cache: 2000 Ko
Lecture de DVD: Oui
CD gravables: -R, -RW
DVD gravables: -R, -R DL, -RW, +R, +R DL, +RW
Stratégies d’écriture: CD-TAO, CD-SAO, CD-Raw, DVD-DAO
ID: MBI 01RG40
Autres gravures: Oui
Vitesses d’écriture: 4x, 6x, 8x, 12x, 16x
Thank you Malcolm, but I already know that DVD-R discs cannot be erased. My problem is that I cannot BURN any DVD, whatever the type: the icon of the DVD does not show on the desktop once a new DVD is inserted in the drive. I have already: tried another DVD, restarted the computer, tried several key combinations on startup, cleaned the DVD's surface, etc. the problem remains, even with CDs... I even bought another SuperDrive, and nothing happens once the media is inserted. I hear the drive run for several seconds, and then nothins happens...
It works only for reading CDs and DVDs
Sorry for insisting...