hi i had psp firmware 3.73(sony's official. then i bought a pandora bttery but when i inserted it i had 4 options. 1-press x to install 3.71 m33 2- press o to install original 3.71 3- press  to dump the nand 4- press l+r+start+home to restore nand dump phisically (dangerous) 1st question: why i don't have dowbgrade to 1.50? 2nd question: after installing 3.71 m33-2 i couldn't play any iso or cso games. i tried putting games in GAME150 folder, i tried putting them in GAME folder but it said curropted data. what i need to do to play the downloaded games?