I have managed to salvage a disk like this in the past with an option in Nero.
On the disc info menu it sometimes allows you to finalise disc.
Ive just burnt a dvd to 99% but it just left it like that with no error or progress, so I left it 5 mins and then pressed eject and still the progress bar didnt notice.
Is there a special program that can finalise disks, the contents are fine Iam sure. Nero isnt showing the option to finalise this time and I cant remember which version it was that showed that it in the past now either.
(Afterwards I noticed that stupid nero had set the option in the disc comp screen to dvd9 instead of dvd5, maybe that caused it)