Dvd burner from 8X to 1.4X MAX

i have been buring for a while. i all ways burn at 8X.
i tried burning and it was flickering from 1X - 1.4X when it burns.
is there a way to fix this. ive tried different dvds ect.
P.S. i cant remeber what model it is sorry

Check the DMA settings of your source and target drive.