I just sucessfully built a minty boost v3 for emergency charging my phone.
Phone : Samsung Galaxy SIIx (SGH-T989D) under Android ICS (4.0.3)
Problem: Phone boots up when charging with Minty Boost.
Description: I was trying to charge it when off but phone keeps booting up when plugging minty boost.
This is not happening with factory wall charger nor USB charging thru computer.
Solution : jump (solder) D+ and D- together. And voila! Phone is charging without turning on.
Hope that can help someone... :D