Originally Posted by eureka
PW updates are recovery updates, meaning theirs validity is also checked with key contained in kernel image.
So you can't repack PW updates without either converting them into non-recovery updates (non-trivial task) or replacing currently installed stock kernel with modified, containing non-Amazon key for checking recovery update validity (over-engineered solution, IMHO; it's also a little bit frightening to flash new kernel on PW without easy access to USB downloader mode in case of accidental failure).
Ah thank you. I remember reading something (it quite possibly was you yourself) mentioning that those full updates use a different mode than the options the jailbreak offers. (That was after I already sent the idea to ixtab, that is why I think he might have left it at that)