SPOOFERS DO NOT EFFING WORK!!!!!
Sorry but for FFS this has come up a few times and I'll say it again....
The reason newer blurays won't work is because the PS3 on firmware 3.55 genuinely doesn't have the keys needed to decrypt them. Bluray keys are updated every few months with a new set of keys, when a new set is used, your playback device will need new keys to play the blurays using the new keys.
We're approximately 5 years into bluray and on roughly version 40 of the MKB keyblock, that's 40 key revisions.
Let's say the PS3 has keys for MKB up to version 30 in 3.55 firmware, it means that any bluray using an MKB version greater than 30, WILL NOT PLAY.
A spoofer is a completely different thing, that is simply a trick to make software you have a higher version number of PS3 firmware installed - Totally different issue. You could have version 999999999999.999999999999 spoofer and you STILL WOULD NOT BE ABLE TO PLAY THOSE BLURAYS DISKS!
(Sorry for being angry....and just read back the OP wasn't actually asking what I thought he was....just saw the word "spoofer" and went bananas )
Anyway, these is no solution, you can't add keys from later firmware as of writing this post.