Test Case:
Code:
<!DOCTYPE html>
<html>
<head>
    <title></title>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <link rel="stylesheet" type="text/css" href="extjs/resources/css/ext-all.css")" />    
    <script type="text/javascript" src="extjs/bootstrap.js")"></script>
</head>
<body>
<script>
Ext.onReady(function() {
    if(Ext.BLANK_IMAGE_URL.substr(0,4)!="data"){                
        Ext.BLANK_IMAGE_URL="./images/s.gif";
    }
    
    Ext.create("Ext.data.TreeStore",{
        proxy: {
            type: 'ajax',
            url:"tree.js"
        },
        storeId:"TestStore"
    });
    
        Ext.widget("treepanel",{
            title: "Tree Test", rootVisible: false, store: "TestStore",
            renderTo:Ext.getBody(),
            width:400,height:600,
            viewConfig:{
                listeners:{
                    refresh:function(view){
                        view.getSelectionModel().select(0);
                    }
                }
            }

        });
    
});
</script>

</body>
</html>
Tree.js
Code:
[
  {
    "id": "all",
    "text": "All",
    "leaf": true
  },
  {
    "id": "ALFKI",
    "text": "Alfreds Futterkiste",
    "leaf": true
  },
  {
    "id": "ANATR",
    "text": "Ana Trujillo Emparedados y helados",
    "leaf": true
  },
  {
    "id": "ANTON",
    "text": "Antonio Moreno Taquería",
    "leaf": true
  },
  {
    "id": "AROUT",
    "text": "Around the Horn",
    "leaf": true
  },
  {
    "id": "BERGS",
    "text": "Berglunds snabbk?p",
    "leaf": true
  },
  {
    "id": "BLAUS",
    "text": "Blauer See Delikatessen",
    "leaf": true
  },
  {
    "id": "BLONP",
    "text": "Blondesddsl père et fils",
    "leaf": true
  },
  {
    "id": "BOLID",
    "text": "Bólido Comidas preparadas",
    "leaf": true
  },
  {
    "id": "BONAP",
    "text": "Bon app'",
    "leaf": true
  },
  {
    "id": "BOTTM",
    "text": "Bottom-Dollar Markets",
    "leaf": true
  },
  {
    "id": "BSBEV",
    "text": "B's Beverages",
    "leaf": true
  },
  {
    "id": "CACTU",
    "text": "Cactus Comidas para llevar",
    "leaf": true
  },
  {
    "id": "CENTC",
    "text": "Centro comercial Moctezuma",
    "leaf": true
  },
  {
    "id": "CHOPS",
    "text": "Chop-suey Chinese",
    "leaf": true
  },
  {
    "id": "COMMI",
    "text": "Comércio Mineiro",
    "leaf": true
  },
  {
    "id": "CONSH",
    "text": "Consolidated Holdings",
    "leaf": true
  },
  {
    "id": "WANDK",
    "text": "Die Wandernde Kuh",
    "leaf": true
  },
  {
    "id": "DRACD",
    "text": "Drachenblut Delikatessen",
    "leaf": true
  },
  {
    "id": "DUMON",
    "text": "Du monde entier",
    "leaf": true
  },
  {
    "id": "EASTC",
    "text": "Eastern Connection",
    "leaf": true
  },
  {
    "id": "ERNSH",
    "text": "Ernst Handel",
    "leaf": true
  },
  {
    "id": "FAMIA",
    "text": "Familia Arquibaldo",
    "leaf": true
  },
  {
    "id": "FISSA",
    "text": "FISSA Fabrica Inter. Salchichas S.A.",
    "leaf": true
  },
  {
    "id": "FOLIG",
    "text": "Folies gourmandes",
    "leaf": true
  },
  {
    "id": "FOLKO",
    "text": "Folk och f? HB",
    "leaf": true
  },
  {
    "id": "FRANR",
    "text": "France restauration",
    "leaf": true
  },
  {
    "id": "FRANS",
    "text": "Franchi S.p.A.",
    "leaf": true
  },
  {
    "id": "FRANK",
    "text": "Frankenversand",
    "leaf": true
  },
  {
    "id": "FURIB",
    "text": "Furia Bacalhau e Frutos do Mar",
    "leaf": true
  },
  {
    "id": "GALED",
    "text": "Galería del gastrónomo",
    "leaf": true
  },
  {
    "id": "GODOS",
    "text": "Godos Cocina Típica",
    "leaf": true
  },
  {
    "id": "GOURL",
    "text": "Gourmet Lanchonetes",
    "leaf": true
  },
  {
    "id": "GREAL",
    "text": "Great Lakes Food Market",
    "leaf": true
  },
  {
    "id": "GROSR",
    "text": "GROSELLA-Restaurante",
    "leaf": true
  },
  {
    "id": "HANAR",
    "text": "Hanari Carnes",
    "leaf": true
  },
  {
    "id": "HILAA",
    "text": "HILARION-Abastos",
    "leaf": true
  },
  {
    "id": "HUNGC",
    "text": "Hungry Coyote Import Store",
    "leaf": true
  },
  {
    "id": "HUNGO",
    "text": "Hungry Owl All-Night Grocers",
    "leaf": true
  },
  {
    "id": "ISLAT",
    "text": "Island Trading",
    "leaf": true
  },
  {
    "id": "KOENE",
    "text": "K?niglich Essen",
    "leaf": true
  },
  {
    "id": "LACOR",
    "text": "La corne d'abondance",
    "leaf": true
  },
  {
    "id": "LAMAI",
    "text": "La maison d'Asie",
    "leaf": true
  },
  {
    "id": "LAUGB",
    "text": "Laughing Bacchus Wine Cellars",
    "leaf": true
  },
  {
    "id": "LAZYK",
    "text": "Lazy K Kountry Store",
    "leaf": true
  },
  {
    "id": "LEHMS",
    "text": "Lehmanns Marktstand",
    "leaf": true
  },
  {
    "id": "LETSS",
    "text": "Let's Stop N Shop",
    "leaf": true
  },
  {
    "id": "LILAS",
    "text": "LILA-Supermercado",
    "leaf": true
  },
  {
    "id": "LINOD",
    "text": "LINO-Delicateses",
    "leaf": true
  },
  {
    "id": "LONEP",
    "text": "Lonesome Pine Restaurant",
    "leaf": true
  },
  {
    "id": "MAGAA",
    "text": "Magazzini Alimentari Riuniti",
    "leaf": true
  },
  {
    "id": "MAISD",
    "text": "Maison Dewey",
    "leaf": true
  },
  {
    "id": "MEREP",
    "text": "Mère Paillarde",
    "leaf": true
  },
  {
    "id": "MORGK",
    "text": "Morgenstern Gesundkost",
    "leaf": true
  },
  {
    "id": "NORTS",
    "text": "North/South",
    "leaf": true
  },
  {
    "id": "OCEAN",
    "text": "Océano Atlántico Ltda.",
    "leaf": true
  },
  {
    "id": "OLDWO",
    "text": "Old World Delicatessen",
    "leaf": true
  },
  {
    "id": "OTTIK",
    "text": "Ottilies K?seladen",
    "leaf": true
  },
  {
    "id": "PARIS",
    "text": "Paris spécialités",
    "leaf": true
  },
  {
    "id": "PERIC",
    "text": "Pericles Comidas clásicas",
    "leaf": true
  },
  {
    "id": "PICCO",
    "text": "Piccolo und mehr",
    "leaf": true
  },
  {
    "id": "PRINI",
    "text": "Princesa Isabel Vinhos",
    "leaf": true
  },
  {
    "id": "QUEDE",
    "text": "Que Delícia",
    "leaf": true
  },
  {
    "id": "QUEEN",
    "text": "Queen Cozinha",
    "leaf": true
  },
  {
    "id": "QUICK",
    "text": "QUICK-Stop",
    "leaf": true
  },
  {
    "id": "RANCH",
    "text": "Rancho grande",
    "leaf": true
  },
  {
    "id": "RATTC",
    "text": "Rattlesnake Canyon Grocery",
    "leaf": true
  },
  {
    "id": "REGGC",
    "text": "Reggiani Caseifici",
    "leaf": true
  },
  {
    "id": "RICAR",
    "text": "Ricardo Adocicados",
    "leaf": true
  },
  {
    "id": "RICSU",
    "text": "Richter Supermarkt",
    "leaf": true
  },
  {
    "id": "ROMEY",
    "text": "Romero y tomillo",
    "leaf": true
  },
  {
    "id": "SANTG",
    "text": "Santé Gourmet",
    "leaf": true
  },
  {
    "id": "SAVEA",
    "text": "Save-a-lot Markets",
    "leaf": true
  },
  {
    "id": "SEVES",
    "text": "Seven Seas Imports",
    "leaf": true
  },
  {
    "id": "SIMOB",
    "text": "Simons bistro",
    "leaf": true
  },
  {
    "id": "SPECD",
    "text": "Spécialités du monde",
    "leaf": true
  },
  {
    "id": "SPLIR",
    "text": "Split Rail Beer & Ale",
    "leaf": true
  },
  {
    "id": "SUPRD",
    "text": "Suprêmes délices",
    "leaf": true
  },
  {
    "id": "THEBI",
    "text": "The Big Cheese",
    "leaf": true
  },
  {
    "id": "THECR",
    "text": "The Cracker Box",
    "leaf": true
  },
  {
    "id": "TOMSP",
    "text": "Toms Spezialit?ten",
    "leaf": true
  },
  {
    "id": "TORTU",
    "text": "Tortuga Restaurante",
    "leaf": true
  },
  {
    "id": "TRADH",
    "text": "Tradi??o Hipermercados",
    "leaf": true
  },
  {
    "id": "TRAIH",
    "text": "Trail's Head Gourmet Provisioners",
    "leaf": true
  },
  {
    "id": "VAFFE",
    "text": "Vaffeljernet",
    "leaf": true
  },
  {
    "id": "VICTE",
    "text": "Victuailles en stock",
    "leaf": true
  },
  {
    "id": "VINET",
    "text": "Vins et alcools Chevalier",
    "leaf": true
  },
  {
    "id": "WARTH",
    "text": "Wartian Herkku",
    "leaf": true
  },
  {
    "id": "WELLI",
    "text": "Wellington Importadora",
    "leaf": true
  },
  {
    "id": "WHITC",
    "text": "White Clover Markets",
    "leaf": true
  },
  {
    "id": "WILMK",
    "text": "Wilman Kala",
    "leaf": true
  },
  {
    "id": "WOLZA",
    "text": "Wolski  Zajazd",
    "leaf": true
  }
]
Use “select”,Firebug :
Code:
o is undefined
return o.id;
Modify the "view.getSelectionModel().select(0);":
Code:
console.log(view)
Firebug:
Code:
 [试用版] Ext.tree.View [0] { id="treeview-1012"}

 [试用版] Ext.tree.View [1] { id="treeview-1012"}
refresh event is triggered two times

Modify the code:
Code:
console.log(view.node.firstChild)
Firebug:
Code:
 null

 [试用版] Ext.data.Store.ImplicitModel-TestStore { id="Ext.data.Store.ImplicitModel-TestStore-all",  internalId="all"}
In the first when the refresh event is triggered, firstChild value is null, and errors.
So, the solution is:
Code:
var node=view.node.firstChild;
if(node){
    view.getSelectionModel().select(node);
}