I have a PGPdisk Volume that I saved to a DVD right before I
reformated my computer.  The volume is 4gigs.
When I tried to copy it back over to my computer afterwards it tries
for a little while and then says: "Cannot copy: Data error (cyclic
redundancy check)"
If I try to mount it from the DVD it says: "PGPdisk mount failed
because: 'this PGPdisk was formatted using the NTFS filesystem, which
cannot be used in read only mode.'"
It's properties cannot be changed from read only mode while it's on the DVD.

How can I recover my data and get this volume back onto my computer?