cd-r backups work but not dvd

[Heli]

Hi everyone

I recently bought my friends chipped PS2 which he bought from thailand the model no is SCPH-39006. I dont know what chip it has but it plays cd-r backups no problem but cant get any DVD backups to work.

I use Datawrite Classic yellow media and nerosmart to burn, so far i have tried the hulk and Tombraider Angel of Darkness.

Any help would really be appreciated.

Thanks Heli