RaiseBubbleEvent can't find parent

[Jeff]

I have a templated composite control with the main parent
control, a container control as its child control, and a
button as the container control's child.

When the button gets clicked, the event gets bubbled up
to the container control but never up to the top parent.
I checked the _parent value of the container control
during OnBubbleEvent and the value is undefined. The
strange thing is that the _parent value was defined when
I added the container to the parent control. Any idea how
to fix this?

Thanks,
Jeff