Im running 6.20 TN-B HEN on a PSP 3000 & like a lot of other PSP users i have been having trouble getting Openidea iso loader to work. Ive been playing around with it over the past few days & today i finally got it working.

Here's a link for the files that i have running on my PSP

Download those & all you have to do is drop the SEPLUGINS folder straight onto the root of your memory card if you don't have one if you already have one just put vsh.txt in your existing SEPLUGINS folder then put my OIP folder into PSP/SYSTEM, disconnect your PSP from your PC, do all the usual stuff with Patapon 2 Demo, Run HEN from the menu & after that's loaded all the games you've put in the ISO folder on the root of your memory stick will run straight from the game menu on your XMB

Here's a video of it working

Games working with no problems
Marvel Ultimate Alliance
Crazy Taxi Fare Wars
Lego Star Wars 2
Shrek Smash & Crash Racing
Toy Story 3
Shrek 3
Hello Kitty Puzzle Party
Family Guy The Video Game
Angry Birds
Astro Boy The Video Game
Star Wars The Force Unleashed
Sonic Rivals
Yu Gi Oh GX Tag Force
Skate park City
Mod Nation Racers
Iron Man

Games i have tested that it won't run
Jungle party
Bejeweled 2
Smackdown Vs Raw 2011
Star Wars Battle Front 2
Ape Escape On The Loose
Everybody's Tennis
Ben 10 Ultimate Alien

All these games work fine on Prometheus ISO Loader. I'll add more after i have tested them.

Hope this helps