iPad tilt gives weird behaviour

Hey folks,

I'm moving a 2D object on the X axis (via transform.position.x) in landscape mode. When I tilt the device past roughly 45 degrees the object stops moving and even the values being displayed for things like rotation stop at the last value prior to tilting past that angle.

I'm calculating the angle with: Mathf.Rad2Deg * Mathf.Atan2(Input.acceleration.y, Input.acceleration.x)

Movement of the object works just fine except, like I say, when tilting left or right past around 45 degrees.

Any thoughts?

Thanks!