First make sure that the fields are fully inside the boundaries of the tab control. When in layout mode, you can select a layout object and use the arrow keys to move it around one pixel at a time. You can confirm if a field or other layout object is fully contained by the tab control by moving the tab control. If the object moves with the tab control, it's contained by the tab control.
Secondly, make sure that no part of the tab control touches or crosses the boundary line between the header and the footer. It won't work right if even one pixel of the tab control touches or crosses that boundary.
Very retentive process. But that did the trick. Thanks