DVD-RW not working!!!

Hello,

i have a strange problem with my DVD-RW. i bought it about 6 months back and used it to burn DVDs only once but frequently burn CDs. Now whenever i try to burn a DVD (using nero) i always get an error no matter whatever i am trying to burn. i have tried updating the firmware and use different DVDs but have failed.

Is there a solution or should i replace mine? btw its an Emprex brand.