I have an idea but I have no way to run with it.
Everyone expects an exploit to be able to do things like downgrade your psp. This may not be the answer since sony patches them.
I have a new idea.
I would love to be able to fool with the 1.5 update eboot... but I don't know how. I think I have to decompile it....
Anyways all you'd have to do is trick the psp into thinking that the 1.5 update is a NEWER version. As far as I know the only standing between an new psp and 1.5 is that message " You already have the most current firmware" or whatever.
Can anyone supply me with a way to experiment.