A problem with Persona 3 Portable

[RinInABin]

Hi, I seem to be having a problem with PPSSPP.

I was playing Persona 3 Portable on my iPhone 4S, on iOS 5.1.1. Everything was running smoothly, 60fps, can get laggy sometimes and some occasional crashes now and then. Nothing serious, really.

But then I got to the part after they battled the Heirophant boss, and everything dropped to 5fps. Even after I reloaded the game, and restarted PPSSPP.

I then tried loaded Patapon. It worked fine before, even better than Persona 3 Portable. But now it was also at 5fps.

So I tried resetting PPSSPP to its default settings. Now, when I try loading a game up, it just blackscreens.
I even tried reinstalling PPSSPP and downloading it from other repos.
I tried using older builds, and the Testing builds.
Still nothing.

A little help?