Ok , untill just now my downgraded psp worked just fine.
But about 10 minutes ago I discovered I can't update to 2.0 anymore!!!
when I press the update (from both umd and downloaded eboot) a screen with no text shows up and I can select X or O , but both options crash the psp.
I hope anyone knows the awnser for this one
edit : I did not use a version changer , and I did reset to factory default.