Why don't you just install 5.00 M33? 2.71 SE-C is ooold, like, what, 2 years? It can't run any of the new games, so there's no point, follow this to upgrade to 5.00 M33;
PSP, all the way from 1.00 to 5.50 GEN D2 - DS Lite w/ M3DS Real (M3 Sakura v1.34)
PS3 3.01 - iPod Touch 2G 16GB Jailbroken - Xbox 360 60GB - PC, Q6600, 3GB DDR2, GTX260 (216) 896MB
M33 is just the new name for the custom firmware versions (They're made by the same person as the OE's). 5.03 is actually the newest firmware, but 5.00 is the latest M33 version there is.
PSP, all the way from 1.00 to 5.50 GEN D2 - DS Lite w/ M3DS Real (M3 Sakura v1.34)
PS3 3.01 - iPod Touch 2G 16GB Jailbroken - Xbox 360 60GB - PC, Q6600, 3GB DDR2, GTX260 (216) 896MB
