Hello,
I've had the same problem of MPU locking-up for a while on my MPU connected to an Arduino Nano,
and for me, the solution was to put 10k pull-up resisters on SDA and SCL lines off the module.
Here's a link to the picture of the wiring; http://www.instructables.com/file/FGI0R61IJD799SO/
and the project is detailed at; http://www.instructables.com/id/Gyro-Stabilizer-W-Arduino-and-Servo/
w.