visible property not honored when alpha is set

Steps to reproduce:
1. rectangle in skin has its visibility bound a boolean value
2. rectangle has an alpha value between zero and one
3. visibility is always true regardless of boolean value

Actual Results:
In example, red border is visible.

Expected Results:
In example, red border should not be visible.

Workaround (if any):
(a) Avoid using alpha values here.
Not sure if this is just isolated to s:Rect or if it replicates with other elements.

(b) Wrap the Rect in a Group:

<!-- this doesn't work unless we change the alpha setting to 1 -->
<s:Group alpha="0.8" visible="

" left="-1" right="-1" top="-1" bottom="-1">
<s:Rect width="100%" height="100%">
<s:stroke>
<s:LinearGradientStroke rotation="90">
<s:GradientEntry alpha="1" color="#FF0000" ratio="0"/>
<s:GradientEntry alpha="1" color="#FF0000" ratio="1"/>
</s:LinearGradientStroke>
</s:stroke>
</s:Rect>
</s:Group>

I think this may be due to display object sharing (or something)