ActiveDirectory programming is not recurning anything

Hi folks.  We are trying to do some ActiveDirectory programming, see the code snip below.  The purpose is by entering a GroupName, we want to list the members of that group.  It works fine on local development machine with IIS running, but it returns nothing when we pushed it to the web server.  Any idea what is going on?  Thanks.

      protected void Page_Load(object sender, EventArgs e)
      {
         GetMembers();
      }

      private void GetMembers()
      {
         try
         {
            DirectoryEntry ent = new DirectoryEntry("GC://cdc.gov/DC=cdc,DC=gov");
            DirectorySearcher srch = new DirectorySearcher(ent);
            srch.Filter = "(CN=DLS_Informatics_Team)"; //DLS_Informatics_Team: the group name.  Manually put in for development purposes.

            SearchResultCollection coll = srch.FindAll();

            ArrayList userNames = new ArrayList();
            foreach (SearchResult rs in coll)
            {
               ResultPropertyCollection resultPropColl = rs.Properties;
               foreach (Object memberColl in resultPropColl["member"])
               {
                  DirectoryEntry gpMemberEntry = new DirectoryEntry("LDAP://cdc.gov/" + memberColl);
                  System.DirectoryServices.PropertyCollection userProps = gpMemberEntry.Properties;
                  object obSam = userProps["sAMAccountName"].Value;
                  object obUserName = userProps["displayname"].Value;
                 
                  if (obSam !=null)
                  {
                     Response.Write(obSam.ToString() + " - " + obUserName.ToString() + "<br>");
                  }
               }
            }
         }
         catch (Exception ex)
         {
            Response.Write(ex.Message);
         }
      }