CEditView inside CFormView (in CDialog)?

How can we get a CEditView to work inside a CFormView sitting inside a CSplitterWnd in a CDialog box?

We have a CDocument1 class that contains a CDocument1a variable. We have written a working CFormView1 and also a working CEditView1a. Now, when we try to use CEditView1a as part of the CFormView1 we get a problem with the m_hWnd of CEditView1a. We tried dynamically creating the CEditView1a object, tried using ClassWizard to have it as member etc. Always crashes on the m_hWnd being NULL or wrong.

Solutions/suggestions?