I went through a huge hassle last week attempting to just restore my phone to factory settings from a jailbroken 2.2.1.

Now, I am running 2.2 with baseband 3.1 and I want to just upgrade to a LOCKED 2.2.1 so my phone is no longer jailbroken.

Is this possible to just use the Update & Restore within iTunes 8.2 running 10.5.7 and let it do its thing WITHOUT bricking my phone again?