MPU-9150 not working

I have connected the Sparkfun MPU-9150 board to an Arduino pro mini and downloaded Pansenti’s Arduino9150 sketch.

Unfortunately no output.

What I get is this:

Arduino9150 starting using device 0

mpu_init failed with code: -1

Everything seems properly connected, Vcc, GND, SDA and SCL.

Can anyone give me some advice?