Scouse, I have the same problem as mr. sir. I followed your guide down to the last dot but when I try to load the cintro I made the PSP just goes black and I have to shut it down. All the other cintros I've downloaded work just fine but I have no luck with the ones I tried making. Maybe the files are too big? I have made God of War III and Monster Hunter 2nd G, around 12 and 11 mb respectively and each probably running at about 2 minutes or more. I've tried to shorten the clip with hopes of reducing their sizes but still I can't play them. Not even on the pmf player.
YouTube - PSP Monster Hunter 2nd G Opening Cinimatic
YouTube - God of War III Teaser