It's been freezing hourly regardless of game, and sometimes doesn't record my save file without reason. When I turn on my DS, half the time it says nothing in slot-1. There's no visible physical damage on the flash cart, and my memory card works perfectly fine (since my AK2 can use it without any problem). So I concluded that my R4 is dead. I guess it lasting 16 months is good enough considering its price. That's all.