Thanks for the recommendation.
SNES 9x runs the game fine on the PSP. The problem is recording the footage via USB from the PSP to my PC. For whatever reason, the footage on the PC becomes choppy and runs at a much lower framerate, even though the game looks and runs fine on the PSP. Strange, but I don't think RemoteJoy Lite is programmed to capture emulator footage, just PSP games themselves.
I'll have to test it with an actual PSP game and see if the problem remains. I recall quickly testing it with a dungeon-crawler RPG called Unchained Blades, and it seemed to work okay with no noticeable loss of frames. I guess it's just the emulated games that lose frames.
I think the best bet is to just buy an HD PVR box and record the PSP via the component output. Recording via USB is just too shifty at times, sadly.