Corrupted files I didn't know I had!

This one is strange... I do a pretty good job backing up my files and keep copies both on and off site. I use LR 3 to catalog and organise my picture files. Yesterday I wanted to create a disk of pictures for a friend, but after exporting via LR, I received a LR message that one or more of the files were not exported because they were either damaged or non supported. Nonsense, I thought, I can see them in LR so there should be no problem. I tried agian, same thing. When I located the files in question in Explorer I found that I was unable to view them in Windows Picture Viewer or any other program. (The files happened to be mostly jpegs.)

I have since ran all the usual diagnostics (Norton's etc) and exported all my library via LR and have found several corrupted files this way, each of which I have sucessfully recovered from a back up.

It would have taken for ever (a long time really) to export a year of pictures at one time, so I exported with:
* JPEG Quality: 0
* Long Edge: 20 pixels
* Resolution 20 pixes per inch

These settings allowed for a quickish export, and provided exported files to verify the integrity of the original file.

I'm not blaming LR for this problem, but have found this thing rather strange. Has anyone else found files which display fine in LR but don't export through LR, and that don't open in Windows Picture Viewer? What have you found to be the cause of the problem?

~Dom

LR is displaying the cache, which means the original RAW file is what's corrupt. I'd replace the disk that the files are stored on.

I guess it's time for a new hard drive! Is there a way I can check for corrupted files without having to see if they export OK through LR?
~Dom

Not that I know of.

Most of the files that I tried to retrieve from my backups were also corrupted, so this is something that happened before the files were saved to this hard drive. I had to go back to a February 2007 backup before I found one where the files were retrievable. Something must have happened to these files soon after February 2007. I have been able to retrieve all but one of the corrupted files from either the pre Feb 2007 backup or other saved projects.

~Dom

Lucky you have incremental backups. I don't, though I have two copies of all RAW data, plus a jpeg copy. I wonder if I should check for corruption.... bit hard.

Sounds suspiciously like a memory problem. You should make sure the memory in your computer isn't bad, it can easily corrupt files and backups over time without you knowing it. I've had it happen to many video clips.

Memtestx86 is free, get the bootable DVD, that's the easiest way to test ram.