I had a problem with older CDs where nested directories couldn't be read past a certain level. If I had something in a directory structure like this:
Victoria
        Clothing
                 Footwear
                          Heels
I could read files all the way down to Footwear, but nothing in Heels.

My old computer (a notebook) could read them, but not the newer ones. I spent a weekend using the old computer to copy files to an external drive and then used that to burn new DVDs. I've now got files on the original CD, newer DVDs, and on two external drives, one at home and one at another location in case something happens to my house.

Try reading reading your disks on an older computer's CD drive/burner.

My visual indexes of Poser content are at http://www.sharecg.com/pf/rgagnon