Code:
Ext.widget("window", {    autoShow: true,
    width: 320,
    height: 120,
    layout: "fit",
    items: [{
        xtype: "treepanel",
        rootVisible: false,
        store: Ext.create("Ext.data.TreeStore", {
            root: {
                children: [{
                    "checked": false,
                    "text": "1",
                    "expanded": true,
                    "children": [{
                        "text": "1.1",
                        "expanded": true,
                        "children": [{
                            "text": "1.1.1"
                        }, {
                            "text": "1.1.2"
                        }, {
                            "text": "1.1.3"
                        }]
                    }, {
                        "text": "1.2",
                        "expanded": true,
                        "children": [{
                            "text": "1.2.1"
                        }, {
                            "text": "1.2.2"
                        }, {
                            "text": "1.2.3"
                        }]
                    }]
                }, {
                    "text": "2",
                    "children": [{
                        "text": "2.1",
                        "children": [{
                            "text": "2.1.1"
                        }, {
                            "text": "2.1.2"
                        }, {
                            "text": "2.1.3"
                        }]
                    }]
                }],
                expanded: true
            }
        }),
        listeners: {
            checkchange: function (node, checked) {
                var i;
                node.removeAll();
            }
        }
    }]
});
When check first node - disappear second node too in chome and firefox.