If you are using dev hook, the UMD you have to have in your PSP. Must be a video UMD otherwise it will not work. For this situation I would really recommend the demo disk that comes with the PSP.
As far as a special loading method for SE-B I never tried to load a video ISO through that, so I really couldn't answer your question. But in the end, just use PMP, its a much better compressed video format, to save space on your memory card. And uses the full resolution of the PSP, just like your video ISO's.
1 God 1 King is truly a king =D He saved me from leaving the scene, but kindly donating his PSP to me. Anybody who talks to him on these forums, is not worthy of his kindness =P THANK YOU 1 GOD 1 KING!!!!