Corrupt CR2 RAW files

Question

Has anyone found a fix for CR2 RAW files being corrupted? I have read all the thread postings I could google on various forums and can not seem to find any solid fix to the problem.
I purchased the Canon 400D for my trip to Asia and shot over 1500 photos, almost all in RAW. I transferred 90% of the images onto CDR and DVD media to make more room my Sandisk Extreme III 4gb card. Of the 1500+ photos, 150+ of my images remain corrupted.
I am posting this in hope that someone has found a fix.
Hardware:
Canon 400D Xti Rebel
Sandisk Extreme III 4gb
Atech Flash Technology "Pro-Gear" USB 2.0 card reader
IBM/Lenovo Z60M desktop replacement
Software:
Canon's DPP (Digital Photo Professional)
Microsoft Camera Raw Viewer (does not work with CR2)
Adobe CS2 with latest upgrades
I filled my CF card up four times during the duration of my trip.
Listed in order:
1 - 6 CDR's
2 - 1 DVD
3 - 3 CDR's
4 - straight transfer from CF card to my Z60m laptop
Of the four times I DL'ed images, the first 4 CDR's were the only folders that did not carry any corrupted files. All files were DL'ed onto a PC using my Atech card reader locally before burning.
Of all the images I took, I noticed a total of about 2 to 3 images that are shown to be corrupted when played back on my camera. I reviewed each and every file anywhere between 1 to 5 times on my camera prior to transfer and they all looked fine (maybe the camera plays back the embedded jpegs?). I would delete all images using the in camera function. I formatted the card before each fresh shoot. Originally thinking it was a CD/DVD transfer issue, that would not explain why some images from the last batch off the CF card (straight from CF card to reader to laptop) were also corrupted.
Here's my workflow (I'm new to RAW): I used Canon's DPP for a day and all the thumbnails displayed perfectly. Like CS2, I believe the software first displays the embedded jpg Thumbnails before loading the actual RAW preview. I did NOT notice any corrupted images based on the rendered thumbnails but I have not verified all my images first before making a strong claim to this.
I have not installed my copy of CS2 at this point and anxious to use Adobe Bridge, I did so the following day. After playing with some images, I began to notice some weird lost of colors in some of my thumbnail preview images. I attempted to open these files and DPP gave me a corrupt image notification. I tried it in Adobe Bridge and the images opened only to show me that either the image had part of it white, black or various colors. Some images were entirely black.
On the advice of a forum poster, I used Fastone Image viewer to see if I can save the image as jpegs and it worked but the jpeg was a smaller both in file size and dimension; not a complete lost at least. I did not recall having any image corruption with the exception of about 3 images (at most) which was witnessed on the camera itself during playback which prompted me to think that there was a bad sector on the CF card.
Notes:
- One forum poster suggested that Microsoft's RAW viewer were causing problems. Originally, I attempted to open one or two CR2 files and MS RAW viewer launched but gave me errors. I DL'ed the latest version and installed it and it will also not work on CR2's. After reading the MS page on the RAW viewer, it shows that CR2 was not supported yet. I then uninstalled the proggie after reading the posting.
- Another forum poster suggests that it is a bad card reader. I will attempt to transfer images directly from the camera going forward.
I'd hate to have this happen again but can not fathom why the problem will not reiterate itself with more RAW transfers going forward. Hopefully, someone has a good solution. Thanks. -Will

Answer 1

Rita,
The process for determining what is causing the files to be corrupt can be a tedious one depending on the following:
1. Can you review the images on your camera's LCD screen without problems? If not then the problem is most probably either a corrupted/faulty memory card or a faulty camera. If this is the case then your best bet at recovery (of sorts) is to use a program such as BrezzeBrowser from BreezeSys to extract the embedded jpeg versions of the corrupted RAW files from within each RAW file. Chances are, you won't manage to actually repair the corrupted RAW file but the jpegs are better than nothing.
2. If the images review ok on your camera but are corrupted when viewing on your computer and there seems to be no other problem with other files on your computer then it may be either a faulty card reader or usb/firewire cable between the card reader and the computer that is the culprit. Try the card reader with a different cable and also try a different card reader to determine the cause of the corruption.
3. If your symptoms are that you get different files corrupting over time when viewing them on your computer then the problem may be any one of either failing RAM memory, hard disk, hard disk controller or IDE/SATA hard disk cables. This is where the troubleshooting can be pretty tedious testing then eliminating each item from the list of suspicious pieces of hardware. Try the card and card reader on an altogether different computer to see if the files transfer correctly to that computer. If so then the problem lies with your computer hardware. If you haven't already done so at this stage, backup all your important data immediately (hopefully you keep backs anyway).
Hope this helps.