2010/7/25 tony.wasserka@freenet.de:
if(pDestRect->left > pDestRect->right || pDestRect->top > pDestRect->bottom) return D3DERR_INVALIDCALL;
if(pDestRect->left > surfdesc.Width || pDestRect->right > surfdesc.Width) return D3DERR_INVALIDCALL;
If left <= right <= Width, left can never be > Width.