can't play homebrew tried everything plz help

okay I am running 3.71 M33-3 my kernal is 1.50 (I did the update for it). I have read tons of help forums but nothing helps. Everytime I put an ISO in my ISO folder it just says corrupted data in my game menu. I managed once to get the image to appear but then it said the game couldnt start. I am downloading 5.01 right now I don't know if it will help. I started with 3.51 then I made a pandora battery then I installed 3.71 M33-2 then updated to 3.71 M33-3 then did update for 1.50. after each step i tried to play games and nothing. i have tried fastloader and umdemulator. Please help. Please. I have a phat psp

Check the link below for proper installation procedures for your iso files.

http://psp.brewology.com/forum/viewtopic.php?t=9454

thank you for replying so quickly. I have done everything on the list but still it says corrupted data. I am going to try formatting my memory stick again. Any other ideas?