Same problem here, no luck with either Sakura, the latest DS Real firmware and one of the older ones, when it was still .0 and not .sav
I... tried around a little with the japanese and english rom, since the japanese worked just fine before, when you add the system.pac and script.pac to the japanese rom and repack it, the M3 DS Real actually loads the game, plays the opening, you get to the character choosing screen and get to pick names for your characters, as the intro text starts the game freezes as soon as the text gets out of the screen.
I am just wildly guessing and may be totally off with my thoughts, since I don't really have an idea about programming, but my guess is it got something to do with the text formatting of the US rom? But the opening should at least load then, shouldn't it...? Ah well, I really don't know...
Hopefully someone will make a fix for this, since I'm dying to play an undub of this game! *sigh*