dvd95 create damaged iso

Hi everyone,
I own several DVD's which I'd like to make a backup copy of. I am trying to use DVD95, as they all exceed the maximum size of a standard 4,7GB DVD.

The problem is that DVD95 apparently creates an iso, and this has even the right size, but when I try to play the film either from the burned DVD or simply mounting the iso image and running VLC, it suddenly crashes and quits.

It cannot be a problem of hardware or drivers, as I tried also to rip the same DVD's with AcidDVD and all went fine.

How could I solve the problem?

Thank you,
bye!