Unable to view ascx control in master page

Hi,
I have a ascx control, which I want to make visible in every page. I have Registered the control in my master page. But I am unable to view the control. Please see my code the way I called.
<%@ Master Language="C#" AutoEventWireup="true" CodeFile="index.master.cs" Inherits="index" %> <%@ Register Src="~/UC/topNavigation.ascx" TagPrefix="uc1" TagName="topNavigation" %> <%@ Register Src="~/UC/SocialIcon.ascx" TagPrefix="uc2" TagName="SideSocialIcon" %> I can see the TopNavigation control properly, But unable to view SocialIcon.ascx in the page. Also, see the HTML where I called it.
<div id="wrapaa"> <uc1:topNavigation runat="server" ID="topNavigation" /> <asp:ContentPlaceHolder ID="ContentPlaceHolder1&quo ...