PlexWriter 16/10/40A SLOW! write problems

Anyone help??? for some reason my plex only burns at x6 with clonecd, any other program like nero or cdrwin dont work at any speed, they just give up after writing the leadin. clone cd does this too if writing speed is selected higher than 6x. I have selected the DMA option on the drive as on too and this doesent seem to help.

can anyone help so i can start enjoying 16x burns?

plz help