DVD-RW 8165 problems

[Inspiron83]

I recently bought a laptop (Fujitsu Siemens Amilo D 7830) that has a DVD-RW/CD-RW combo drive. It can read CD's, DVD's fine and can even burn CD-R's with no problem. But it refuses to burn DVD's. I use Nero Express 6 for all my burning processes. I either get 30-40% done with a DVD and it says "illegal disk" and stops the burning. I am burning a extracted movie and it plays the burned parts just fine. So i tried burning data and got the same thing, either go about half through and stop or stop at the very begining. Any idea as to what might be the problem? I do belive the drives brand is Ricoh, not sure though Thanks!