burnable media not recognized as such
 

I'm using a Plextor PX-716A DVD Burner with the 1.08 firmware, and seem
not to be able to burn anything.

I insert the media into the drive, try to then burn a few small files
to the media with Nero Burning ROM, and immediatly after that, the
media is ejected and I get a message telling me to insert an empty disk
for writting. The only problem is... the media *is* empty.

I've tried burning on the following media:

Memorex 16x DVD-R
Memorex 4x DVD+R
Maxwell 4x DVD+R
Memorex 52x CD-R

I'm also unable to read DVD movies with the drive. Cyberlink PowerDVD
6.0 sees the drive as empty as does Windows.

Any help would be appreciated. Thanks.