Embedded Modeless Child Dialog not getting message

Question

I've got a three pane MFC application where one of the panes is a modeless dialog that will be swapped dependent upon options being selected from a CTreeCtrl in another pane. The modeless child dialog instantiates as expected and OnInitDialog is called, however clicking within that pane does not result in the mouse clicks being processed. That is the message map in the modeless dialog class is not being called. Any ideas??

UPDATE: I decided to rethink my code. What had been a modeless CDialog being swapped in a splitter window became a CFormView instance that I was able to dynamically swap after setting the DYNAMIC_SPLIT flag in the application. Everything works now and the code is simpler. Thanks all!