🚀 go-pugleaf

I have a problem with the refresh of the TImage component:
with the Builder 5 Professional if I call the Invalidate method of the 
TImage class, everything is ok.
If I compile the same program with the Builder 6, as soon as I call the 
Invalidate function (or Refresh, or Repaint) the image flashes.

The only way to avoid this effect is to put the TImage directly on the form 
(without using any Panel) and to call theWindows API:

 RECT  Ret;
 Ret.left=ImageCor->BoundsRect.Left;
 Ret.top=ImageCor->BoundsRect.Top;
 Ret.bottom=ImageCor->BoundsRect.Bottom;
 Ret.right=ImageCor->BoundsRect.Right;
 InvalidateRect(Handle,&Ret,false);

But if I use the canvas of the Bitmap to trace a rectangle, I have again the 
flashes.

Is there any property to set (of the TImage, of the Form or of Panel) or any 
way to avoid this effect?

Thanks for the attention.

Cherubino