when a CalloutButton is inside a scroller, callout cannot be closed by clicking 'on' it

Steps to reproduce:
1. Compile and run the following:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
applicationDPI="160">
<s:VGroup>
<s:Scroller width="100%" height="100%">
<s:Group>
<s:CalloutButton left="20" top="20" label="Callout">
<s:Button label="Hello" />
</s:CalloutButton>
</s:Group>
</s:Scroller>
<s:CalloutButton label="button">
</s:CalloutButton>
</s:VGroup>
</s:Application>

2. Click on the "Callout" button to open the callout
3. Click on the "Callout" to close it

Actual Results:
it is not closed. compare with the calloutButton ("button"), outside of scroller.

Expected Results:
it should be closed.

Workaround (if any):