MPU-9150: Accel data interpretation

I managed to get the raw data from Accelerometer. Its set for 2g and here is what i get:
-688, -6, 15604

While on the flat surface it should produce 0,0,16384. And tolerance is said to be 80 on x and y and 150 on the z, so these values are not really correct.
Any idea what can be the cause?

Thanks!