Make sure you change it to
FLASH 512kbytes then click
OPTIONS>Save option>File>Reset Cartridge and you are all set. Try to use your creative. Look around in no$gba's options. That's how I figure it out on my own about a year ago. It is not so hard.
@ Jale, it's corruption because 64k is wrong savetype for it. It is
FLASH 512kbytes.
Yeah, I know.. I am master at no$gba things, lol!