So im just about to start downgrading my PSP, but I first have to upgrade from 3.11 to 3.50. So I've downloaded 3.50 from http://dl.qj.net/PSP-Firmware-3.50-(North-America)-PSP/pg/12/fid/13840/catid/163 and ive put it into the PSP/GAME/UPDATE folder but it only shows up as 'corrupt data' and it wont let me upgrade? just wondering how to fix this. Also, once im done downgrading do the emulators use special 'PSP roms' or something? or just regular ones? Thanks.