Need Help backing up Xenosaga for PS2

This one is giving me problems. I put the original disk in my dvd-rom drive and windows reports it to be a 3.96 GB disk. When I try to burn it in Alcohol 120% or create an image using DVD decrypter they both report it to be 7.89 GB. I can’t backup the images they create to my DVD+R disks. If anyone could help me I would greatly appreciate it.

someone has to have some idea how to do this.

Never mind. I found out that Xenosaga is a DVD-9 with hidden files. It would take 2 or 3 disks to back it up, not to mention a headache. I’ll just take my chances with damaging my original.