Hello all, I am new to the forum, but I decided to create an account because I am killing myself over here over this problem I'm having with my Canon 1Ds. A little history: I purchased my 1Ds as my first venture into full-frame digital photography and was thrilled when I got it in the mail. Sure, the camera is 11 years old and half a dozen newer models have come out--still, it is a great camera. I just looked at my eBay history yesterday and was reminded that I purchased this camera on November 1, 2013. This means I have had a little over a month of problem-free shooting in glorious full frame. When I purchased the camera, it came with one Kingston 8gb 133x CF card, a strap, Canon 28-105mm lens (damaged, but still working, if only in autufocus mode) and battery charger. Since then, I have purchased a spare battery and now two new CF cards (which I hadn't opened until just last week). However, when I came back the other day from shooting on the coast in Northern California, I came across a problem. As I took the original (from the previous owner) CF card and attempted to copy the photos to my computer, my computer refused to recognize the CF card. I blame this on the reader I had, a cheap plastic thing that was constantly falling a part. An Amazon prime purchase and two days later, I had a new card reader. I tried it on another computer and it worked fine. I then copied the pictures onto my laptop. After properly ejecting the card, I put it back into my camera and turned on my camera to find . . . nothing. Despite a full charge, the only part of the camera that functioned with the old CF card was the rear LCD screen, displaying the AWB, RAW and Card indicators. I was surprised that neither the top LCD screen nor the rear LCD monitor (where the pictures are displayed after being taken) would work. Additionally, none of the buttons worked. I thought that was weird, but when I turned the main power switch to the "off" position, suddenly the top LCD screen turned on. However, none of the buttons worked and the LCD monitor still displayed nothing. Worried that I could not operate it and could not turn it off, I removed the battery and then took out the CF card. I thought that possibly something was wrong with the card. No worries, I thought, I have a Kingston 16gb 266x CF card as a backup, just in case I needed it. I had never tried it with the camera, however, as I hadn't needed it up to that point. Well, when I put the memory card in the camera, normal functions seemed to have resumed: the menu buttons worked, the correct screens lit up and I was even prompted to format the card. I smiled to myself as I selected the ok button to format my card, thinking, "good, you didn't just spend $500+ on a heavy paperweight." Three hours later, the progress bar on the format screen was still completely grey (i.e., had not even begun to format) and "busy" was still displayed. This now gave me plenty of cause to worry. I am not a wealthy man and cannot afford to buy a new camera. My mind began going through all of my options, when I stopped at what I thought was possibly a pretty good reason for it to not work: perhaps the 16gb 266x CF card was simply too new or fast to be used with such an old camera. No worries, I thought (well, some worries) -- I will just have to try another smaller, slower card with the camera. As I put in my purchase order, I also fired off an email to Canon support, hoping there was a simple solution to the problem (or that they had at least heard of the problem before). Their reply scared me. They gave me seemingly standard advice for if anything goes wrong with the camera (turn it off, remove the lens and battery, clean lens contacts, try a different card, try resetting settings (not even an option on my camera's menu)). Then they reminded me of something I already knew, that Canon no longer services this model. They did tell me about the Canon Loyalty Program, but something tells me that even at a "discounted fee," I won't be able to afford a comparable refurbished model direct from them. I was still holding out hope, however, for the new slower memory card. Well, I received it today. And I'm sad to tell you that I am now writing this post hoping somebody, somewhere, has seen this problem or knows how to fix it. I have contacted the seller of the item on eBay (he's out of town for the holidays of course) and asked him about the warranty that was included with the camera when I purchased it. Hopefully that will pan out to something, but as of right now I am at a loss about what to do. I didn't really spend this much money for a month and a half of joy, did I? tl:dr Used Canon 1Ds memory card makes camera go wonky; camera stalls on reformatting new CF cards. PLEASE HELP!