title: Pull to refresh and list pagging duplicating records on listing page
body: <p>I am new for sencha touch.  I have a Listing page which using Ext.plugin.PullRefresh and Ext.plugin.ListPaging plugin to refresh my page, but I'm having an issue with duplicate items appearing after I pull to refresh. </p>
  
  <p>Here is my coding</p>
  
  <p>~View</p>
  
  <p>Memberlist.js</p>
  
  <pre><code>    Ext.define('bluebutton.view.BlueButton.MemberList', {
      extend: 'Ext.List',
      xtype: 'memberlistcard',
      requires: [
          'Ext.field.Select',
          'Ext.field.Search',
          'bluebutton.view.BlueButton.MemberDetail',
           'Ext.plugin.ListPaging',
          'Ext.plugin.PullRefresh'
  
      ],
      config: {
          iconCls: 'team1',
          title: 'Member List',
          styleHtmlContent: true,
          scrollable: 'vertical',
  
           store : { xclass : 'bluebutton.store.BlueButton.MemberList'},
          grouped: true,
          indexBar: true,
           limit: 5,
         plugins: [
                      { xclass: 'Ext.plugin.ListPaging',
                        autoPaging: true },
                      { xclass: 'Ext.plugin.PullRefresh' }
                  ],
  
          id :'memberlist',
          items: [
  
              {
                  xtype: 'toolbar',
                  docked: 'top',
  
                  items: [
                      {
                          xtype: 'selectfield',
                          name: 'gender',
                          cls: 'txtwhite',
                          options: [
                              { text: 'Active Member', value: 'both' },
                              { text: 'Delete Member', value: 'male' },
                              { text: 'Suspended Member', value: 'female' }
                          ]
                      },
  
                      { xtype: 'spacer' },
  
                      { xtype: 'searchfield' ,
                           itemId:'membersearch',
                           id :'membersearch'
                      }
                  ]
              }
          ],
          emptyText: '&lt;p class="no-search-results"&gt;No member record found matching that search&lt;/p&gt;',
          itemTpl: Ext.create(
              'Ext.XTemplate',
              '&lt;div class="tweet-wrapper"&gt;',
                  '&lt;table&gt;',
                      '&lt;tr&gt;',
                          '&lt;td rowspan="2" width="1%"&gt;',
                          '   &lt;img src="{imgUrl}" width="170" height="170" /&gt;',
                          '&lt;/td&gt;',
                          '&lt;td&gt;',
                          '   &lt;div class="tweet"&gt;',
                          '       &lt;h2&gt;{memberId}&lt;/h2&gt;',
                           '      &lt;h3&gt;Name: {name}&lt;/h3&gt;',
                          '       &lt;h3&gt;Age : {age}&lt;/h3&gt;',
                          '       &lt;h3&gt;Address : {address}&lt;/h3&gt;',
                          '       &lt;h3&gt;Point Avalaible : {pointAvalaible}&lt;/h3&gt;',
                          '       &lt;h3&gt;Last Visited : {lastVisited}&lt;/h3&gt;',
                          '   &lt;/div&gt;',
                          '&lt;/td&gt;',
                      '&lt;/tr&gt;',
                  '&lt;/table&gt;',
              '&lt;/div&gt;'
  
  
          ),
  
  
  
      },
  
  
  });
  </code></pre>
  
  <p>~Store</p>
  
  <p>Memberlist.js</p>
  
  <pre><code>Ext.define('bluebutton.store.BlueButton.MemberList', {
  extend: 'Ext.data.Store',
  
  config: {
      grouper: {
          groupFn: function (record) {
              return record.get('name')[0];
          }
      },
  
      fields: ['memberId', 'name','age' ,'imgUrl','address','lastVisited','pointAvalaible'],
        pageSize: 5,
         autoLoad: false,
          storeId :'memberlist',
  
      data: [{
          memberId: 'Kenny',
          name: 'Kenny Chow',
          imgUrl: '/bluebutton/resources/images/user3.png',
          age: '20',
          address:'The Business Centre , 61 Wellfield Road , Roath, Cardiff, CF24 3DG',
          pointAvalaible :'10',
          lastVisited: '26/11/2012, 11:52 AM',
  
  
  
  
      }, {
          memberId: 'Anthony',
          name: 'Anthony Tan',
          imgUrl: '/bluebutton/resources/images/user3.png',
          age: '21',
          address:'3 Edgar Buildings , George Street , Bath , England , BA1 2FJ',
          pointAvalaible :'44',
          lastVisited: '27/11/2012, 09:52 AM'
      },
  
      {
          memberId: 'Nicholas',
          name: 'Nicholas Chen',
          imgUrl: '/bluebutton/resources/images/user3.png',
          age: '22',
          address: '91 Western Road , Brighton ,East Sussex ,England ,BN1 2NW ',
          pointAvalaible :'30',
          lastVisited: '30/11/2012, 15:52 PM'
      },
  
      {
          memberId: 'Admin2',
          name: 'Admin2',
          imgUrl: '/bluebutton/resources/images/user3.png',
          age: '30',
          address: '50 Eestern Road , Brighton ,West Sussex ,England ,BN1 34W ',
          pointAvalaible :'120',
          lastVisited: '01/12/2012, 15:52 PM'
      },
  
       {
           memberId: 'User2',
           name: 'User2',
           imgUrl: '/bluebutton/resources/images/user3.png',
           age: '25',
            address:'Office 33 ,27 Colmore Row ,Birmingham, England ,B3 2EW',
               pointAvalaible :'32',
  
                lastVisited: '30/11/2012, 18:52 PM'
           }
  
  
  
      ]
      }
  });
  </code></pre>
  
  <p>Please help. Thanks</p>