I was really unlucky while choosing the medium, it was apparently bad.

There was the additional problaem that cdrecord was unable to get 
session information which made me beleive the driver is broken.
Iirc I got always some session information on GNU/Linux. But I am not sure
what cdrecord version I had.

thanks
-- 
Michal Suchanek
hramrach@centrum.cz