BNO055 Occasional Register R/W Fail

Hi. I have a BNO055 sensor shield from Arduino. I am facing a problem while reading the configuration registers ACC_CONFIG and GYR_CONFIG.

When I power on the sensor, the reading/writing to these config registers fail. Then I run the unit for sometime and restart it a couple of time and then it starts reading normally. I am wondering what is causing this.

Anybody experience something similar?

Thanks