Hi...
I'm having the same problem for months, but since it was only with GBA games, and partly because I wasn't playing very often, I did't care.
But now, after 10+ hours of Final Fantasy IV gameplay I got a corrupted save, and everything was erased.
I noticed that this happens when I play the game, turn off and try to play after a day or more without having initialized the system. The backup thing somewhat fail and I lost the data.
Did anyone find a solution?
Sorry if I didn't make myself clear. English is not my first language, so don't blame me.