How to set SkinID of a control contained in a composite server control?

[Pawel Krakowiak]

I have a composite server control and I create some dynamic controls in it, like so:

public class MyControl : CompositeControl
{
private Panel panel;

protected override void CreateChildControls()
{
	// Clear controls.
	Controls.Clear();
	
	// Create controls.
	panel = new Panel();
	panel.ID = "Panel1";
	panel.SkinID = "Panel1"
	
	// Add controls.
	Controls.Add(panel);
}

protected override void Render(HtmlTextWriter writer)
{
	panel.RenderControl(writer);
}

}

The said server control is placed on a page which uses a stylesheet theme, which has a skin file containing a declaration for a Panel skin, like so:

<asp:Panel SkinID="Panel1" runat="server" BackImageUrl="top-panel.gif"></asp:Panel>

However, the skin is never applied... Am I missing something or doing something wrong? Perhaps CreateChildControls override is a bad place to do that?