Missing and not working events in TFrame component

Does anyone have any experience with frames, quite useful new feature in BCB
How can I tell, when frame becomes active in runtime and respond? It does
not have OnActivate or OnShow or similar event. Second, the WheelMouse event
doesn't seem to work. Not in the frame, not in the controls, for which the
frame is container. I have DBGrid on frame and neither frame nor grid
receives WheelMouse event. Just parent form does. It is a "feature" or a