I have an idea that could possibly help narrow down the file needed for the 3.60 PSN access. Im not sure if its possible or easy to do but i will post it none the less. If someone Started up their PS3 for the first time in a day and tried to sign into PSN (on 3.55 so it looks for the correct key or w/e it is or on 3.60 so it will be successfull) and record the time you signed it (or attempted) then remove the Hard Drive from your PS3 and plug it into your computer (obvs you need the right connection) and look for files that were modified/used around that time?
Is something like that possible? Or would they not be time stamped per say?
Sorry if this is a stupid idea or something :P