How to draw shapes at whole pixel coordinates?

Whenever I draw a rectangle in Flash CS6, it never seems to be drawn at whole pixel coordinates, despite using a 100% zoom level. Instead, its x-coordinate is always some fractional value like 0.65.

This occurs with all snapping turned off, as well as with just pixel snapping turned on. With pixel snapping turned on, the width and height of the rectangle are whole numbers, but its x-coordinate is still fractional.

Is this some kind of bug or does anyone know how to fix this?