I recently got a DSTWO, and noticed this as well. It's annoying, but at least once you have 10 saves, the emulator starts overwriting the 10th slot, so you can be lazy and just keep saving without deleting anything without creating hundreds of saves. But that doesn't help if you want to easily maintain multiple save states.
GBA emulator related question: I loaded some cheats files, and I believe I did it correctly because the emulator does recognize and list them, but when I activate them, they have no effect. They list as "on" but there's no in-game change. I've tried loading them both before running my game and after it's started, but neither seems to work.
I'm playing Castlevania: Aria of Sorrow (USA release) and using the corresponding gbatemp .cht file, if that helps. Does anybody know why I can't get the cheats working? Thanks.