I have the GPS attachment for my PSP and it hasn't gotten along very well with any firmware past 3.40 OE, which is OK because TM lets me install 3.40.
My question is though, can I install older firmwares using this method as well? The firmware it worked best with in my experience was 3.03 OE-C, and I'd love to get it up and running for when I want to use my GPS. Any idea if or how this could be done? And if nobody knows, could I mess up my PSP at all if I just grabbed the 3.03 update and renamed it to 340.PBP?
Come to think of it, I may have an archived Flash0/1 from my 3.03 PSP laying around here... could I just put that in the place of the 3.40 fies?