CF Error

So I was at a local nature preserve today and I took a bunch of photos. I set up for another shot and my LCD screen flashes "CF (Compact Flash) Error" and didn't allow me to take anymore pics. I headed home and downloaded my pics, formatted the card, and its working just fine. Reminder to self: buy a back-up CF card. After I downloaded the pics, it turns out some were corrupted. The pics
shown here were not edited or collaged, this is how they came out of my cam.