Setting Z-Index on UIPanel

[phenotype]

Strange problem I am trying to set the z value on the transform of the UIPanel gameobject but the value is being altered. First here is the line that changes the z value;

1. MyDialog.transform.position = new Vector3(MyDialog.transform.position.x, MyDialog.transform.position.y, this.Sequence)
2.  

where Sequence is an integer that represents the order in which they are displayed.

If I set the value to -1, the actual value appears as -241. If I set it to -2 the actual value is -482 and the UIPanel disappears outside the view.

Is NGUI changing this value? If so, what is the best way to layer panels for display?

[ArenMook]

You're setting the absolute position. Inspector shows the local position.

[phenotype]

switched to;

1. MyDialog.transform.localPosition = new Vector3(MyDialog.transform.localPosition.x, MyDialog.transform.localPosition.y, this.Sequence); 
2.  

And everything works fine.

Thanks