Backup DVD Probelms

Hello Every one,
i recieving this error when i am trying to backup my Dvds,
"CAN ONLY COPY First Data track"

I am using Nero burning rom version 6.0.0.9. i couuld easily backup my dvd discs without using dvd shrink or decrypter but now i am not able to copy discs with it. can any one plase help. if you check the disc after it has been bunt you can see that only a small sector has been burnt. my nero version is full version i reinstalled it as well but no luck.

my system spec are

2.8 Gh Pentium 4
512 DDR Ram
DVD Writer Pioner 108 dual layer

Thanks,
Masood