i have a Galaxy S II Skyrocket that turns on when i plug it into my Belkin USB-CLA car charger. if i shut it off it just comes back on. i have found that this charger does not have the D+ and D- contacts on the usb connector shorted together. my house chargers do have them shorted together and they do not have this problem. if i short them together in the car charger it fixes the problem. it does however cause the phone to draw 50% more charging current. if i put a resistor between 10,000 to 47,000 ohms between the D+ and D- terminals in the charger it fixes the "turn on" problem and does not cause the charge circuits to go into fast charge mode. this prevents the charger from having to supply more power than it may have been designed to supply.
it seems the phone tests these leads when it is plugged into a usb port and if it finds an open circuit , it assumes you are connecting it to a computer and need to transfer data. then it turns on the phone so that it can connect with the computer.
hope you find this info useful.
