new cdrom burner on powerbook doesn't work

[Giuseppe Sacco <giuseppe@eppesuigoccas.homedns.org>]

Hi all,
I just replaced the internal cdrom of a powerbook itanium g4. The
previous one stopped working some months ago when the laptop fallen down
:-(

The new one (CD/DVD reader, CD writer) is the same model as the previous
one (8121A) and it works quite well sith MacOSX.

With my Sarge I may read CD and DVD but I cannot burn new CD. I have two
different behaviours:
1. sometimes the new media is just ejected
2. sometimes the new media is "accepted", then I run cdrecord and it
recognize the media too. then cdrecord tell me that the driver need to
reload the media (this is different than what happened with the previous
drive, but cdrecord is also a new version), it ejects the media, I
reinsert the media and the burning starts. cdrecord complete the burning
operation without errors but then the cdrom isn't readable, i.e., it
cannot be mounted (even on a different computer).

Does anyone have an idea on what to do?

Thanks,
Giuseppe