since many have been having the same problems in making of a pandora battery, pls look here.
the most common error i have heard of lately, is that u put in ur battery, ur lights flash, and nothign happens.
This is because u have made ur magic memory stick wrong.
for a full guide on how to make a battery and stick:
YouTube - Install Pandora's Battery Without 1.50orCFW (SLIM+FAT PSP)
this is the video that worked for me!
also: if u have windows vista, the truth is that U CAN make a memory stick on it
i did!
all u have to do is when running command promt as seen in the video to format the memory sitck, u have to right click on the icon. Then click run as administrator.
in the video on the side, there are links to the files for 3.80 M33, and 3.71 M33 (i did 3.71 M33 and im still on it)
I hope i have helped u guys in need.

__________________
I like potatoes! If u like rock then.... u rock!
3.80 OFW--> Pandora --> 3.71 M33-2--> 3.90 M33-2

Ive hacked 5 PSPs including my own. THX Dark_Alex!