Download and study the sample window and library scripts I included in this post:
Glass Pane Tutorial
The way mouse events are passed through the overlayed component works properly for all Vision components. The library script locates the deepest component under the mouse that actually has a mouse listener and dispatches the event there. Some Vision components contain inner subcomponents that actually handle the mouse events, so simply using the outer component itself fails since the outer component doesn't have the necessary listener.