10 DOF Mems IMU Sensor

It seems that 10 DOF Mems IMU Sensor is very affected by magnetic fields. I test it in different experiments with the wheeled mobile robot. If wheels motors are switched off then sensor works well. But, if motors are switched on then sensor output wrong values (in particular, angular velocities). I don’t expected this, because such sensors are usually used with a moving dynamical objects equipped with a motors.
Is somebody faced with this problem? And how to overcome it? May be some screening or some another solution?
Is somebody faced with this problem? And how to overcome it? May be some screening or some another solution?