With Mike Hilder's help, I have loaded both the Mere Mortals Framework Infragistics Windows Controls.pdb and Mere Mortals Framework.pdb in order to permit the breakpoints in the MM.NET code to be accessed.
(These are located at C:\Program Files\Mere Mortals.NET Framework 2003\Third Party Components\Infragistics Windows Controls and C:\Program Files\Mere Mortals.NET Framework 2003\Mere Mortals Framework)

I am using the Infragistics mmUltraTextEditor so I looked into mmUltraTextEditor.cs from the Infragistics Controls project as well as what you have suggested.
I did not find a StateChangeHandler() method in mmTextBox.cs (or mmUltraTextEditor.cs)

In the region ImmBinding Members, I found public virtual void OnBindData method.
I placed my breakpoint in this method's mmBindingStrategySimple.BindData(this, bindingSource, e); code line.

This breakpoint was never reached while running the code with the Dim WithEvents CSForm As New CompanySelectionForm code line uncommented. The form loaded and no databinding occurs (all fields are disabled and empty - including my navigation grid).

So... obviously my declaration of an object reference that includes WithEvents is somehow interferring with MM.NET databinding of controls.

Any thoughts?