I'm trying to upgrade from 4.2.1 to 4.3.3 using redsn0w. I go through the process and it looks like its working but when the phone restarts and I look in About it still has 4.2.1.
I just did exactly that two days ago. I backed the phone up using iTunes and with PKGBackup to Dropbox, then restored to 4.3.3 using iTunes, then restored from my iTunes backup, then Jailbroke using Redsnow, installed PkgBackup, restored from that and bam, I was on 4.3.3 with no need to manually resintall anything else and no data loss.