Bitmap printing -> tiny printed picture ??

[Cruonit]

When i call this procedure to print a bitmap loaded from a file(the bitmap is a desktop capture 1280x1024) the printed picture is much much smaller!(about 240x190)

a sample output(print to pdf):

Output Sample

void PrintBitmap() {
     CPrintDialog printDlg(FALSE);
     printDlg.GetDefaults(); 
     CDC dc;
     dc.Attach(printDlg.GetPrinterDC());
     
     // Initialise print document details
     DOCINFO di;    
     ::ZeroMemory (&di, sizeof (DOCINFO));
     di.cbSize = sizeof (DOCINFO);
     BOOL bPrintingOK = dc.StartDoc(&di); // Begin a new print job 
     dc.StartPage();                      // begin new page

     // Get the bitmap from disk
     CBitmap bitmap;
     bitmap.Attach(::LoadImage( ::GetModuleHandle(NULL), "C:\\temp1.bmp", IMAGE_BITMAP, 0, 0, 
                                LR_LOADFROMFILE | LR_CREATEDIBSECTION | LR_DEFAULTSIZE));
     CDC memDC; 
     memDC.CreateCompatibleDC(&dc);
     CBitmap *pBmp = memDC.SelectObject(&bitmap);

     BITMAP bm;
     bitmap.GetBitmap(&bm); // for width and height

     // copy to printDC
     dc.BitBlt(0, 0, bm.bmWidth, bm.bmHeight, &memDC, 0, 0, SRCCOPY);

     memDC.SelectObject(pBmp);

     if (bPrintingOK)
       dc.EndDoc();         // end a print job
     else dc.AbortDoc();    // abort job. 
}

any ideas ?