Troubleshooting Imgburn and DVD Decrypter (I/O Error)

Hello,
I have made around more than 100 backup DVD copies first with DVD shrink and then DVD Decrypter or ImgBurn. For your information, I have the newest version of ImgBurn and newest supported firmware in my DVD burner. Till now TY02 discs are my best choice. I have never experienced a bad burn but suddenly anyhow I am getting I/O errors. I thought may be there are problems on the discs and consider them as being faulty.
But I am getting perfect burns using the same discs and software in another burner on my desktop. Then I have checked both DVD drive and hard drive, the both are DMA enabled. I have also tried burning at slower speeds than 8x but again getting the same I/O errors.
Now I really don't know what to do, could anyone provide me any kind of help?
