I have an iPhone 3GS w/ new bootrom running 3.1.3, but unfortunately only have 4.2.1 shsh blob saved. I selected "erase all content and settings" from the phone itself, after which, the phone freezes at the bootscreen when the wheel shows up. From what I have read, the only way to get this to go away is to restore through iTunes, but I am desperately trying to avoid updating the firmware (since Apple will not allow me to restore from the 3.1.3 IPSW file). From my own research, it appears that I am S.O.L., but am hoping someone else might know something I do not. Thank you in advance.