Hmpf!

I had about 4GB of processed scientific data that I wanted to get off the individual Systems and burn on a DVD.

As an intermediate Solution, I collected everything on a DVD-RAM.

Yesterday, that DVD-RAM was full and I decided to burn it onto a Regular DVD+RW for permanent storage.

Now, Nero6 copied the Files directly from the DVD-RAM and burned all of them onto the DVD+RW (File compare was 100% okay after the process).

But :
Today, I needed to look something up on the DVD+RW, just to find out 3 different DVD Drives can't read anything from it.
There definitely is Data on the Disc, but I can't access it, therefor I must assume the Files were not burned in the standard Data Mode, but (possibly) in DVD Video Mode

Is there any way to check what went wrong and (if possible) copy the Disc back into a usable Format again ?

If not, I lost about 8000 hours worth of Science, which would suck big time

There are some ideas and a utility or two on these sites:

http://www.signvideo.com/btst-d.htm

http://www.vso-software.fr/checklist.htm

Can you make a raw image (bin, cue or iso) of the whole dvd (all tracks)? I remember using a program that could extract files from  those images back in my linux days. I used it with a cd that was unreadable under windows. But i can't remember it's name. When there are no physical errors on the dvd where the files are stored then there must be a solution to rescue the files. Whe you succeed making an image then you can look at it with a hexeditor. Maybe you recognize if your files really where burned.

Regards,
Andreas

Maybe you find usefull programs here:
http://www.heise.de/software/default.shtml?kat=221&s=se&l_sw=1&l_aw=1&l_fw=1
and here:
http://www.heise.de/software/default.shtml?kat=222&s=se&l_sw=1&l_aw=1&l_fw=1
All links german!

Regards,
Andreas