I recently bought the M3 and have been running the most recent Sakura firmware (1.4 I think?). I have an 8 gig card I just bought, plus an older 1 gig card. My problem seems to be that during some games the M3 will lock up (music/sound get super garbled but the screen just freezes). When I restart sometimes it's only a black screen or a white screen. So it can take multiple restarts to get to work. Games like Brain Age rarely freeze (I can play for hours a day, multiple times a week and it may freeze only once). A game like Castlevania freezes a little more often, but a game like Elite Beat Heroes will freeze frequently at the end of a song. I've reformatted both cards multiple times with the special formatting software off of this site, left a few hundred megs to gigs open on each card, I even tried the paper trick, all to no avail. I may just buy a CycloDS because this M3 has been terrible.