edit box cant get focus

i have some problems and because i dont know where to look for the
error, i post some description...

i have a propertysheet with some pages and i have another dialog
(CRecall). what i want to do is to put the 2nd page of my sheet
(DlgErweitert) into a static window (m_REParent) of CRecall.

that looks like this:

BOOL CRecall::OnInitDialog() {
  CDialog::OnInitDialog();
  RECT rc;
  m_REParent.GetWindowRect(&rc);
  ScreenToClient(&rc);
  rc.top += -GetSystemMetrics(SM_CYCAPTION) -
GetSystemMetrics(SM_CYBORDER);
  DlgErweitert->Create(IDD_ERWEITERT,this);
  DlgErweitert->MoveWindow(&rc,true);

DlgErweitert->ModifyStyle(WS_CAPTION|WS_DISABLED,WS_VISIBLE|WS_CLIPCHILDREN,1);

 // ... //
  return false;
}

now the problem:

the dialog is correctly displayed and also is my propertypage in it,
i can click/modify the radiobuttons and checkboxes, but listboxes
and editboxes wont get the focus if i click into them (but they do
change mouse cursor correctly while mouse is over them).
If i set initial focus to one of the editboxes, i can write into them,
but when i click into some other area of the dialog (CRecall) or
into a checkbox/radio of the propertypage, i cant reset the focus
by mouseclick.

so ... where do i have to look for this error?

btw, setting above return value to true doesnt any good.

thx for any help;-)