I keep offline backups on DVD and find the last six months of 2009 "missing" for unknown reasons. The DVD used has a UDF file system, shows June's 250 MB of files accessible as expected, but the rest of the disk is shown full, apparently of nothing. Disk is updated monthly (typically a 600MB parcel of files that arrived or changed since last backup) until full, normally checked after the write to verify contents; I can't guarantee this was done after the 7th write, but that check must have been done several times in the full compilation period of this DVD.
I use Sonic MyDVD+ for writing, work under XP and do scrap the occasional DVD that cannot be written. The troublesome DVD is Verbatim brand. Have tried ADRC image backup/restore, got a 4 GB .img file, but this re-burnt as the original, 250 MB data on a "full" DVD. All the file recovery software I can find does not appear to deal with UDF systems.
That's a bad hole in my records. I'd really like most of those files back. Can anyone suggest a software or manhours approach I could try to recover the data?