Unbearable load times

[Ciaran_Zagami]

I'm new to emulators as a whole, my PSP's thumb stick died last week and after some shopping I decided that its cheaper to run PPSSPP instead of buying a new one.

I've only tried two games so far, Persona 3 Portable runs fine. But on Metal Gear Solid Peace Walker and the load time is UNBEARABLE.
I put my ISO in the emulator, it opens like normal. the game checks the memory stick exactly like how it does/did on original hardware, and then a loading screen.
I've been sat here for five minutes waiting for this to end and it makes no progress.

Is there anything I can do to speed this up? Is my ISO corrupted?
Persona loads in less than 10 seconds after I open it so I assume the emulator is working fine.