i burned files in my dvd using nero 7. then i aborted the burning process because i forgot to add some files. after that i checked my files and it shows that my dvd is empty. when i tried burning it again a small window appeared saying that my dvd is not empty, and that my previous files won't be accessible again if i continued burning. i tried finding my previous files but i can't find them. do you know how i can get back my files again? please desperate call. thank you