Here's the page:
https://www.testmasters.net/test/ssltest2.aspx
When I go to it (in firefox or chrome), it says "connection partially encrypted". But all references to objects are https and not http as far as I can tell.
What's odd is that if you remove the RequiredFieldValidator, the page works fine. Here's the source (ASP.NET 3.5):
<%@ Page Language="C#" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>SSL Test</title>
</head>
<body>
<form id="form1" runat="server">
<div>
SSL Test #1
<asp:TextBox runat='server' ID='textDude' />
<asp:RequiredFieldValidator runat='server' ID='requiredDude' ControlToValidate='textDude'
Display='Dynamic' />
</div>
</form>
</body>
</html>