problems w/ pops on 3.71 m33-3

I haven't played any ps1 games on psp for a few firmware versions now, and now I can't seem to get any running. I'm trying to get Chocobo's Dungeon 2 working, but no matter what I do it always gives me "This game cannot be started". I have all of the pops plugins and have pops enabled, have it on 3.71 kernel, and don't have a custom opening .rco, and those seem to be the only solutions google can find for me. I also have two versions of my iso on the psp, one w/ keys.bin and one without. Any suggestions are appreciated.