Overburned DVD data recovery

[mrideout at windserve.com]

Hi,

I have a cron job that backs up a FreeBSD server's files to DVD+RW media
each evening using growisofs from the dvd+rw-tools port. There are some
files that I need to recover, but the problem is, the last 2 weeks of
backups were a few hundred megabytes too large, and overburned.

Is there any way to recover data from these overburned DVDs? I tried
mounting them from FreeBSD, Windows and Mac systems without success. I
also tried running "cat /dev/acd0 | gzip > data.iso.gz" in an attempt to
grab the raw bits of the disk, but that only resulted in an input/output
error.

Restoring a 2-week-old backup is an option, but any ideas on how I might
read data off of these overburned disks would be greatly appreciated.

Thanks,

Matt