still cannot get iso or cso of mgs portable ops to work

[BillH23]

I have other iso and cso games that work fine. I have tried three different mgs files they all show on my psp on the memory card. But once i got to boot it up the mem card light blinks a bit then freezes for a min or two and then the psp shuts off. I am running cfw 5.00 m33-6 with kernel 150. Note I also had mgs portable ops plus working. I am at my wits end here and really want to play this. I even converted the original file from cso to iso and then after that did the same thing shortened the files name and it still does the same.