I have an old SD card image that I bought along with a raspberry pi back in June or so (Debian was preloaded onto the card). Very recently, I bought several new blank cards and a several new raspberry pis. I copied the SD card multiple times and tested each copy in the original, working raspberry pi--every duplicate worked perfectly. However, the duplicates would not boot in the newer raspberry pis... They simply output no video at all. Has something substantial changed in the hardware where a disk image from a few months ago will not boot in the newer raspberry pi units?