MPU6050/MPU6500/MPU9150/MPU9250 library over I2c

Hello! Using AvrCopter project to run the arduino Uno with MPU 9150.
It runs ok. But for a few seconds only I get some results, after that I receive the following error:

Seems like the quaternion check fails. its out of range. and never comes to normal range. So

ret = mympu_update();

after few seconds starts returning 3.

Before there was an issue with firmware compare failure. Which I fixed by setting Fastwire speed from 400 to 200.

No trying to understand the nature of this error I saw the following comments:

  • We can detect a corrupted FIFO by monitoring the quaternion data and
  • ensuring that the magnitude is always normalized to one. This
  • shouldn't happen in normal operation, but if an I2C error occurs,
  • the FIFO reads might become misaligned.
  • Let's start by scaling down the quaternion data to avoid long long
  • math.
    */

How can I find out if there was a I2C error (if that was the cause)?
In any case how can I resolve the issue?