Hi Kim, even though we have 3 Canon cameras I do not use Zoombrowser. I just use files and folders explorer to copy and paste them to my hard drive.
.cr2's are Canon's raw file format. Apparantly the .cr2 is still on your card.. so that is a good thing. There is a possiblity that particular .cr2 was somehow corrupted.
If your compactflash card is LEXAR... Lexar has a small program called Imagerescue2 [for Mac and PC]. I think it will attempt to recover the image file on your CF. Lexar software came on the compact flash card. http://www.lexar.com/software/image_rescue2.html
SanDisk RescuePro - http://www.sandisk.com/Products/ProductInfo.aspx?ID=2195
Other image rescue found here
From Canon Support EOS 20d KnowlegeBase was no help
Issue: How can I restore deleted images?
Solution: Attempt to use image recovery software or contact a data recovery company.
If images have been accidently deleted from the computer and/or the camera's memory card, third party data recovery software or data recovery companies may be able to retrieve the images. Canon does not bundle any type of image recovery software with our products. We would suggest contacting your computer or memory card manufacturers for possible suggestions and/or perform a web search for data/image recovery.
Forum Moderator for
EasyPano - Panoweaver