Forgive me if I'm 'tarding up the thread here, but Kakaroto said he can run signed code, but not unsigned code. Now, by definition, the HEN would have to modify some of the files in the PS3's NAND, whether it be on the NAND itself, or in RAM (since it's a HEN, it would be in RAM). Theoretically speaking, couldn't he also modify the version number in RAM, which would then allow the official 3.55 updater to run, thereby downgrading; or is there a piece of the puzzle I'm missing here?
I'm a bit of a n00b to the PS3 scene, I only got one recently, it WAS on 3.55 at one point, but it was on 4.00 by the time I got it. I was, however, very deep into the PSP scene (I was one of the few people that was told about the Pandora battery before it was public) and Wii scene back in the day