When resizing a spark TitleWindow with a TextArea, using event.updateAfterEvent() causes flicker

Steps to reproduce:
1. Run attached sample for ResizeBug.mxml and ResizeDecorator.as
2. Select the leftmost edge of the 'Test Window' panel, and drag to resize

Actual Results:
Right most edge of the TitleWindow flickers unexpectedly.

Expected Results:
Smooth resizing , as found when TitleWindow contains (i.e.) TextInput.

Workaround (if any):
Don't use event.updateAfterEvent() after every resize.