40D corrupted images

I took a trip to Baraboo Wisconsin recently to photograph the Whooping Cranes they have there. I filled three cards, a Trancend 4 gig, a Sandisk 2 gig, and an older Sandisk one gig. All the shots were RAW and all looked great on the lcd but when I got home and started processing them I found out that about half of the files were corrupted. I sent the camera back to Canon today. I am wondering if any of you have had a similar experience with the 40D. I just read a thread in dgrin from a guy who had cards die in his 40D.

How'd you move the pictures from the camera to the computer? Corrupted files are at least as likely due to problems with a card reader or the USB cable as the camera proper.

When you say filled the cards do you mean down the the last shot? When shooting raw I have read it best to always leave 1 or 2 shots of space left on the card as RAW is data and can vary from shot to shot on the size of the file. I have never seen it corrupt a card myself but I tend not to want to take the chance.

I loaded the cards using my Sandisk card reader. When I noticed the corrupted images I tried reloading with the card reader in my computer tower. Same corrupt images in both tries. As far as the cards being totally full, only the 2 gig card was filled up. The others had between five and ten shots left on each card.