I'm trying to install 5.50 Gen D3 on my PSP (1001). When I bought it, it had 3.71 firmware on it and I cannot update it past this firmware. Whenever I try to update it says that the memory stick cannot be read. It is an official Sony memory stick. My guess is that someone fucked up in the installation of CFW sometime in the PSP's past, because I did buy iy used, is there any way to fixed this or should I return the PSP?