Ok. Im sitting here playing on ver 7.2, and its laggy, so i look for a dif one. and i find one. but its ver 4.0, so i think it wont work. but i put in a game that is buggy for ver 7.2, like, after the menu all itd show is a black screen, but on ver 4.0, not only did it pass that and show whats next, but it was also about 10xs faster than 7.2. the only problem i can find is that theres no sound and no save state.

Now, my question is this. Why is ver 4.0 compatible with Final fantasy III and some other games i have, but ver 7.2 isnt?