The Slider (and all UIComponents) rely on direct access to the 'stage' - which is denied due to recent AIR 1.5 security restrictions. This restriction prevents any UIComponent from working when loaded into an AIR app as a local SWF. The parentSandboxBridge cannot return a reference to the stage.
Does anyone know of a workaround?
The best solution is to modify the UIComponents to listen to a parentSandboxBridge for Stage events. It is impossible for the inner SWF to observe the Stage directly.