dvd shrink burning issue/ navigation issue

I saw a navigation issue in another thread but my issue went a bit farther. I received two dvds. the first one i backed up and decrypted with dvd shrink and left the file on my computer. the second i couldn't even get on dvd shrink. I tryed to open the disc on dvd shrink and it kept saying - invalid dvd navigation structure. so i tryed using dvd decryptor and that came up with some error too. I gave up on that one and went to burning the first one i saved. When i went to burn it it kept saying failed to burn - after it encoded. it gave the reason - invalid disc or something like that. Can anyone help me? Be easy on me I am not just a newbie here but to burning discs too. I really have a limited knowledge of this sort of thing. I would also like to add that the discs I have been using when the failure came up are the same ones I have been using in the past. I have a detailed list of what dvd shrink said after the failure if you would like to see that let me know and i will post it. Thank you for your time. wolfie.