ASP Windows authentication - Authorziation not working for Active Directory groups

Hi
I have a site using Windows authentication, and I am wanting to limit access to the site by Active Directory user groups.  My problem is that my user groups don't appear to work on our live server, but they work fine on our development server.
My web.config contains the following:
<authentication mode="Windows"></authentication> <identity impersonate="true"/>    <authorization>
    <allow users="DOMAIN\username"/>
    <allow roles="DOMAIN\ActDir Group 1"/>     <allow roles="DOMAIN\ActDir Group 2"/> 
    <deny users="*"/>   </authorization>
I am using Windows authentication in my IIS and anonymous is turned off.  My live server and development server are on the same domain, and look to ...