2 things spring to mind
1 firmware in dvd drive, your burning software should be able to tell u what is currently loaded to your drive (nero roxio). once u have that check on your laptop manafacturers web site to see if there is an update or pioneers site or some of the web sites that deal with standalone dvd players have a section for in pc/laptop drives.
2 its donald ducked !
there are differences the way cdr's and dvd's are writen at 1 stage they used different heads (that may be different now) so it is quite possible that 1 will work and the other wont.
a pioneer drive i have a few years ago was fine untill i bought some 8x discs even though i tried to burn at 4x untill i updated firmware then the drive would burn the discs at x4, it was something to do with the media being recognised.
if u struggle to find firmware give us a shout with laptop make model etc