Multisession DVD MP3s - Problem with compilation

I burnt some MP3 music into a DVD disc but when I added few more MP3 files to the compilation, I accidently hit the delete button on a folder from the first compilation. Now, though I can see that first compilation as recorded in Track 1, I cannot access it. The capacity of the DVD has reduced to 3.29 GB. The balance 1.5 GB is for the first compilation, which windows or Nero does not read. Is there anyway that I can retrieve the first compilation?

Try to access the first comp with Isobuster