I didn't have any problems with it for the first couple of days I played it, but then I started getting freezing when I'd go to the inventory screen. Not long after that I got a corrupt save file. I'm using a DS-Xtreme with the latest firmware. I also had a corrupt save file from Asphalt Urban GT a week or so earlier and then right after the corrupt save file with the castlevania game; mario kart had a corrupt save. I formatted my DS-Xtreme and have added Portrait of Ruin onto my cart, but I am a little afraid to start playing because I don't want to lose two days worth of progress again. I'm hoping that maybe I just didn't leave enough space on my cart for saved games, but in reality, it's probably just an issue that could be addressed with the next firmware update.
lol i never thought about defragging the memory card.
Oh well I just went out and bought the game for sakes of collection and it really was worth it! Awesome game!
Linear Mode
