I have a project that is using the SD card on the official Arduino Ethernet Shield. It was working fine, but not any more. Now it hangs on the declaration of a file:
File file_CODES = SD.open("CODES.txt");
The SD card is initialised successfully. If I try to list the files on the card I don't have problem. I haven't changed any libraries. I've formated the card on the computer and still no change. Any ideas what else I can check.