XT strange sensor issue - anyone seen this before?

My wife took this picture with her Rebel XT - this was the only one showing this behaviour out of about 800 shots taken that day. Has anyone seen anything like this before - it sure is some sort of sensor issue, but what could have caused this?
EXIF: ISO 400, f/8, 1/800sec, taken with the 100-400L at 400mm, no flash.

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Suspect it's not a sensor issue- more like a file corruption issue
Brian V.

Good point, didn't think of that. That makes much more sense. Thank you for the quick reply. All other files on that card were fine - I guess I'll tell her not to worry about it. We were afraid her camera might be dying.

Looks like your CF card is f-ed up, not a sensor issue. Try a different card.

Edit: dang, lordv beat me to it

Format your card in your computer and see. If you have a sandisk card you should have an image recovery tool, no sure if it will work, but it's worth a try.

Thanks everyone. She's not that concerned about recovering this particular image - she has plenty of snow geese pictures from that day and as I said, all other pics on that card were fine. It was a Kingston 4GB card btw.

The XT probably isn't dying, but your CF card might be.

Format the card and be on the lookout for any more corruption. CF cards have a limited number of read/write cycles before they will start to fail. If you start to see more files with corruption, go ahead and toss the card or save it only for an emergency. (A CF card that might corrupt is still better than no CF card.) You can probably get a few 4GB cards for the same price you might have paid for that card originally.