[UPDATE 6/3] CAUTION! If you already have unlocked iPhone, restoring iPhone just by clicking ‘Restore‘ button without holding ‘SHIFT‘ key will cause iTunes erased ALL media and data, and you will lose your unlock since iTunes will install newest iOS version for your iPhone.
[UPDATE 5/31] You can get out of recovery by using TinyUmbrella or RecBoot.
You may encounter error error 16xx or 2x during custom firmware restore on iTunes. The message such like this:
The iPhone “-” could not be restored. An unknown error occurred (16xx). Continue reading
The `i` Technology Projects 