MPU2950 Accelerometer values

[FreaktheBear]

Dear Mika,

I connected a new MPU2950 sensor and this one initialized okay and with the code from Kevin McLeer I was able to calibrate the magnetometer.
However the pitch and roll values don't make any sense to me at the moment.

When the sensor is horizontal, it produces the following readings:
X: 3.122039 Y: 12.07875 Z: 8.492233 Pitch -0.1 Roll 0.8 compass 358.5931 Heading N

When I roll it 90 degrees I get the following readings:
X: -5.145139 Y: 12.24395 Z: 2.858677 Pitch -2.3 Roll 35.0 compass 125.3656 Heading SE

I would expect to see a Roll of 90 degrees. Also the x-y-z values are not what I would expect.
I have done similar tests with a MPU6050 sensor which produces values from -1 to 1 G for all three axis depending on how the sensor is oriented.
When the MPU6050 is held horizontal, x and y give approximately zero G and z gives 1 G.
Would you be able to give me a hint on what I should check?

Thanks in advance