Notice at the bottom of the SD Loader screen (after a while) it says "Real Checksum Value" and "Checksum Value" (or something like that). What you have to do is open the crc file in notepad (or some other text editor) and replace what is there what is after the "0x" in "Real Checksum Value". Or you could get the crc value by running the nb0 file through the crc calculator, found at
Download CRC_calc.rar, upload your files and earn money.