Single sign-on with Forms Authentication not working on IE

Dear Friends,
I'm using Single sign-on with Forms Authentication Which is based on tutorial of Hernan de Lahitte (http://weblogs.asp.net/hernandl/archive/2004/06/09/ssoformsauth.aspx).
I have done some basic changes according to requirement of my project.
Following is the code I've done:
Web.Confg:
<authentication mode="Forms">
  <forms defaultUrl="home.aspx" loginUrl="Login.aspx" timeout="20" slidingExpiration="true" cookieless="UseCookies" name=".ASPXFORMSAUTH" protection="All"></forms>
</authentication>
<authorization>
 <allow users="*"/>
</authorization>
<machineKey validationKey="128bitKey" decryptionKey="64bitkey" validation="SHA1" d ...