OpenGLControl shuts down parent's timer

I'm observing a strange behavior that I don't understand.

The program I've uploaded into this thread is a watered-down version of a larger one. Recently, I had some assistance from VladimirF concerning the z order of child windows in this program, but now I have a new problem that leaves me scratching my head. I original thought it was a z-order problem again, but I'm not so sure.

In the background of the parent window, I've embedded an OpenGLControl-derived object that I've called "m_DrawingScreen". The trouble is, when I create the object, the parent dialog never receives a timer message that it normally receives when you hit the "Expand" button at the bottom left.

To see what I mean, comment out the following line located in MainDialog near the bottom of CreateDynamicControls function.

Code:

---

m_DrawingScreen.Create(OpenGLControlRect, this);

---

When you comment out that line, you'll notice that hitting expand sets off a timer that slowly scrolls two dialogs into view. This behavior is shut down when you let m_DrawingScreen be created.

(Incidently, there is a crude cage drawn in the DrawingScreen that you can sorta rotate around. It is probably not relevant to this problem, I think, but it is neat to me.)

Anyway, if anyone can point me in the right direction for the solution, I would appreciate it. Also, please let me know if I've forgotten to include any files. Thank you.

Sorry, it doesn't contain the binary file.

I'm not sure I understand. What is the binary file? I don't see any files in my project that say binary file. :(

Does anyone have any ideas for this?