I just jailbroke/unlocked my 3G for resale and I have this question: will I have problems upgrading from my jailbroken 3G to my iPhone 4 arriving Tuesday? Will I retain my settings, etc. or can I even do it at all from a jailbroken backup? Do I need to first go back to my pre-jailbreak backup before I do the upgrade? After that I could do a clean restore on the 3G and re-jailbreak it. Any insight would be greatly appreciated. Thanks.