Im gonna try upgrading my 3GS from 3.1.2. to 4.0.1. and the only JB. I have SHSH stored in cydia, so i need to edit hosts-file, put phone to DFU, shift-click restore and select downloaded .ipsw.

I have currently JB done with blackra1n, does this affect anything.

I want to get confirmation which iTunes version i can safely use? i Now have 9.0 so i think i should update but can i use version 10?