But if you do format the ms, you will also lose everything else that is on the stick. If you can spare the space on the stick (or better if you have a spare stick) keep the mms in case of any mishaps in the future. Then, if you have a semi brick just bung in the mms and the pandoras battery and the job's a good 'un. R
or you can change it from pandora to normal and back by the touch of a button i got this one its great works as a normal spare battery when you finished pandora-ing http://www.focalprice.com/1200mAh_Pandora_Battery_Pack_for_PSP1000_2000_White_GP059W_7922.html
format it in you psp under system or a pc card reader then it gone 1st i'd back up the files to the pc just incase you want them again