Same MediaCode, but diffrent speed avaible with my burner

I have an DVD Burner in my Notebook (UJ-845D Mathsita) and i have to DVD-R with the same MediaCode FujiFilm03, one from Phillips and one from



It is excact the same, except the available Write Descriptor.

My Burner can Burn the Disc von Phillips 8x, but the Disc forum Intensio only with 2x. Does someone Know what is the reason for that ?