Hi! im new here. i just bought my slim psp. accidentally, i updated its version to 3.90. the result was that whenever i copy-paste my .cso files to the iso folder, i can't see the files when i open the games menu in my psp. also, when i tried to reformat my memory stick, the iso folder was missing. the folder in psp are: ms_root, music, psp, video, and picture folder. help please. thanks!