Just recieved a sony psp 4gb mem stick. (bought at best buy) However, psp 1000 will not boot from sleep or coldboot with new mem stick inserted or no mem stick at all. Only old 2gb will allow it to boot up. When new is inserted, only green power light is on, no orange light. When booted with none same thing. 5.00m336 japanese psp1000. Idk what the prob is, any ideas? Btw, if booted w/2gb then can switch out to 4gb and it works and reads the information. Thanks... I can only check replies from cell phone so i'm not able to respond immediately. Thanks again in advance.