Question printing a bitmap

[Atreides]

I wrote the attached code to print a bitmap (PNG format).  The pointer
bitmapImage points to a valid bitmap. Compiling and running the code
(release , unicode, 8.2.7, Windows XP) I am observing two pages in the 
preview window, the first one contains the bitmap and the second one 
seems empty. Printing I got no problem, but  only one page is printed.
Compiling in debug mode I got ( using the preview and changing the 
previewed page from the first page to the second ) the following assert 
error.

..\..\include/wx/dynarray.h(813): assert "uiIndex < m_nCount" failed in 
Item().

I got this assert even printing the image.

Rescaling the bitmap (making it smaller) I get only one page in the 
preview and no assert.

Please could you help me to understand where I am doing programming 
mistakes in the following code?

void PngViewer::OnPrint( wxCommandEvent& event )
{
   wxRichTextCtrl ctrl(this);

   wxRichTextPrinting *ctrlPrinting  = new 
wxRichTextPrinting(wxT("Printing PNG Image"),this);

   wxPrintData *pPrintData = ctrlPrinting->GetPrintData();


   pPrintData->SetOrientation(wxLANDSCAPE);
   pPrintData->SetPaperId(wxPAPER_A4);
   pPrintData->SetQuality(wxPRINT_QUALITY_HIGH);
   pPrintData->SetPrinterName(wxEmptyString);

   ctrl.Clear();
   ctrl.BeginSuppressUndo();
   ctrl.WriteImage(*bitmapImage,wxBITMAP_TYPE_PNG);
   ctrl.EndSuppressUndo();
   ctrlPrinting->PreviewBuffer(ctrl.GetBuffer());

   return;
}

Thanks

Max