2 DOF gyro problem

Hi

I connected a 2 DOF IMU (ADXRS401 and ADXL203) through 10bit ADC.

when the IMU is horizontal and still, I read appr. 512 from the accelerometer and from the volt reference. The gyro reading is appr. 555! shouldn’t it show 512? (1024/2). I connected the temperature pin and read 510, meaning the reason for the deviation cannot be because of temperature difference.

Why do i get high reading from the gyro? should i use the ST1 or ST2 to adjust the gyro? how do I use these connections?

Thanks in advance

Please excuse my poor inglish. I really try…