SVG Limitations

There's a bug with Flash that causes strokes (object's borders) to appear too small when the stroke's thickness is 0.5 or lower.

When strokes are 0.5 or lower, Flash will render the stroke as a hairline stroke. That is, an infinitely small one that always takes up one pixel no matter how far you zoom in.

For this reason, you should avoid any strokes of 0.5 or lower.

Note that it's possible to have a SVG file that specifies a stroke greater than 0.5, but if the object is being scaled down due to a transform the stroke will be reduced. If the final reduced stroke is less than or equal to 0.5, the issue will appear. Similarly, it's fine for an SVG to specify a stroke of .5 or less if the object is being scaled up.