NM_HOTSPOT / Notifications for HTMLControl in C#

[Hutch]

I am looking for some thoughts on this.

I have successfully gotten the HTMLControl to work using C#, and it is
displaying HTML and receiving messages nicely. Unfortunately, I am
not able to receive notifications from the HTMLControl.

In an attempt to support this, I added a private MessageWindow derived
class to the control, instantiating it in the constructor (of the
control).

Unfortunately, I am not receiving any messages from the HTMLControl.
I do receive a single message on the initial load of the form (13) but
not from the handle of the display window the control is using.

I have not found much documentation on the MessageWindow, aside from
the NotifyIcon example - which I followed. I thought that adding
notifications would be rather simple when looking at that code.

So, I am looking for thoughts on how to debug this - or where to look
next. My options seem straight forward:
1. The control isn't producing messages and needs some initialization
to do so.
2. It is producing messages but not directing them to where the
MessageWindow can receive them.
3. The MessageWindow should be receiving them, but isn't properly
setup to do so.

Any thoughts on what to do next?