Which automation library are you using? Did you try to click it manually with the mouse?
We would like to use FlexMonkey.
First of all, I added "-include-libraries "$/libs/automation/automation.swc" "$/libs/automation/automation_agent.swc" "$/libs/automation/automation_spark.swc"" to the project's compiler arguments in Flash Builder.
After compilation and execution, the controls are manually non clickable.
After some tests, it seems a Group overlap all the controls and catch the click events with the automation libraries.
Without automation libraries, the click events pass through the Group.
When I set the attribute mouseEnabledWhereTransparent to false for Group and subclass objects, transparent zones don't catch mouse click event anymore and it is possible to click the controls under the Group.
Hope this will help!