Im on vacation in Beijing China and took my new official 3.40 PSP with me. This was a month ago before the new noobz 3.50 downgrade system.
They took my PSP to the back and opened it to crack it and when i got it back i recieved "3.10OEA'R+" firmware under system settings.
I dont know exactally what they did to my PSP to downgrade it, i was actually shocked that they did it i though it wouldnt hurt to ask if they can add custom firmware to it.
Mabye here in China they have their own s because i dont see anything in english when i google it (im still in china using chinese version of google) there is nothing in English about it.
I did eventually upgrade to Dark Alex 3.40OEA myself so i can play smash court tennis if anyone cares to know.
In case anybody is curious it cost me 200 RMB ($25 USA dollars) to customize my 3.40 official PSP (they charged more because they had to take it apart) you just walk in and ask, and when you get your PSP back you can sit there at a computer and they help you add games to your memory card for free!! they sell the cd's full of games here. its so crazy here in china but that is a different topic.