Hey, I posted on this thread a while ago, but I never got a proper response.
When I updated my game to v4, I attempted to play it on my savefile, saved in v3. However, it froze as soon as I did an action such as talking to a NPC. I had to downgrade to v3 in order to play the game.
I am playing on DesMuMe 0.9.6 x86.