When i connect the output of the regulator to the board, there is a mysterious voltage drop from 8V to about 4V at the voltage divider. This voltage is in turn fed to the regulator so the output of the regulator is now about 2.5V instead of 5V.
I'm using a 330 ohm resistor(R1) and 680 ohm resistor(R2) for the voltage divider with a supply voltage of about 12V. Also im powering the board from the 5V breakout pin of the board.
Anyone please help me understand what is going on??

Albert.