1) what is the type of screw for use with the memory door? 2) Can I somehow fix the inner memory slot so the PB can have more memory? I have the old memory installed in it but it doesn't recognize it- is there a way to make work again? 3)what battery would recommended? Are there any better ones and how long do are these suppose to last? I have an aftermarket battery from Amazon since the original died and the battery seems to discharge quickly so its better to keep it plugged in.