SIP not showing in LAP password validation dialog

I am not getting the SIP (on-screen keyboard) to show when the
password validation dialog is shown. The password validation dialog,
the one that shows when the device starts up, is part of a custom LAP
that I fashioned of Marcus Perryman's example at
http://blogs.msdn.com/marcpe/archive/2005/12/06/500591.aspx.

The code used to display the dialog is essentially
case WM_INITDIALOG:
{
SHINITDLGINFO shidi;
shidi.dwMask = SHIDIM_FLAGS;
shidi.dwFlags = SHIDIF_SIZEDLGFULLSCREEN;
shidi.hDlg = hDlg;
SHInitDialog(&shidi);
SetForegroundWindow( hDlg );
SHSetNavBarText( hDlg, TEXT("Password") );
}
I've tried a number of different options with the shidi.dwFlags but
it does not seem to solve the problem. Am I missing something?

Any help or suggestions would be welcome.

.