having the same problem.
got a psp with a 3.11 firmware.
been looking for answers everywhere and all ended up with
"there's no downgrader for 3.11... /(yet)..."
my real question is, is there really a downgrader for any of the 3.10 to 3.40 official f/w?
and if there is, is it possible for me to update my 3.11 to the said official f/w that can be downgraded so that i can upgrade to a custom firmware...