I've had the 520 close to a year now, and apart from a couple "Copy Err" incidents (spread over time and not repeated), it has been very reliable. I use TDK 4x -RWs for some works in progress, such as clip compilations. Today, I was adding one 8 minute segment to a half-full -RW disc. (In case it matters, the segment was heavily edited down, from what was originally much longer material.) This segment was edited inside the Copy List, whereas my former practice had always been to cut down the actual recorded video. This one addition seems to have totally trashed the disc. Around the end of the copy attempt, I got an error to the effect of "Can Not Copy Video." At that point, I think I could still see indexed thumbnails for the prior disc contents. A tray eject of the disc automatically triggers "File Write." This led to another error, "Could Not Repair Disc." Now the disc is rejected / not recognized or readable by the 520 as being a compatible disc. I tried to access the disc on the PC, using the only thing I have that I thought might be appropriate, DVDXRESCUE. It shows no contents, no tracks . . . but this is an older program that perhaps has no ability to deal with VR formatted discs (?) None of the installed players could find anything there either.

So, my initial question to you (hopefully more learned folks) is: Is everything on this trashed -RW disc now toast, or is there some way of retrieving it ? Could ISOBUSTER do the job, bearing in mid that this is a rewriteable, made in VR format and unfinalized ? Or is there some other tool I should consider ?

Maybe the Copy List type of "virtual editing" I did is inadvisable, or maybe my confidence in the reliability of the DVR was misplaced. But I tell you this: just as it is important to back up your conventional data work -- whether text, db, spreadsheet or whatever -- I now realize the importance of periodically backing up video work in progress too. I have copied unfinished -RWs to finalized -Rs a few times, using Nero's Copy Disk, and definitely regret not having done so in this case. I mean, so you waste a couple of blanks, but it's cheap insurance.