And can you try like DXDraw1.TextureFilter(0) ?

Code:
  if not DXDraw1.CanDraw then Exit;
  DXDraw1.BeginScene;
  {set texture filter explicit here}
  DXDraw1.TextureFilter(0);{0..4 - like D2D_POINT, D2D_LINEAR, D2D_FLATCUBIC, D2D_GAUSSIANCUBIC, D2D_ANISOTROPIC}
  DXImageList1.Items.Find('bckgrnd').StretchDraw(DXDraw1.Surface, Bounds(0, 0, DXDraw1.Width, DXDraw1.Height), 0);
....