Jailbroken to 3.55? You can't install regular (debug) PKG files on it. You shouldn't have rushed. You can only install signed PKG files (like demo games or other official applications at the moment).
I just need to transfer some saves to my PS3 that are blocked like Assassin's Creed II. Is there anyway to do that on 3.55CFW or do I have to wait two weeks for someone to crack this baby open? Also isn't hombrew support up for this version of CFW?