When Ext.grid.feature.Grouping feature and Ext.grid.plugin.DragDrop plugin are used together on a grid, dragging a record into another group throws errors:

Code:
Uncaught RangeError: Maximum call stack size exceeded
There's an infinite loop of method calls:

Code:
...
Ext.cmd.derive.setLastFocused
Ext.cmd.derive.focusRow
Ext.cmd.derive.onRowFocus
Ext.cmd.derive.onLastFocusChanged
...
Ext.cmd.derive.setLastFocused
Ext.cmd.derive.focusRow
Ext.cmd.derive.onRowFocus
Ext.cmd.derive.onLastFocusChanged
...
Sample code:

Code:
var store = Ext.create('Ext.data.Store', {
    storeId:'employeeStore',
    fields:['name', 'seniority', 'department'],
    groupField: 'department',
    data: {'employees':[
        { "name": "Michael Scott",  "seniority": 7, "department": "Management" },
        { "name": "Dwight Schrute", "seniority": 2, "department": "Sales" },
        { "name": "Jim Halpert",    "seniority": 3, "department": "Sales" },
        { "name": "Kevin Malone",   "seniority": 4, "department": "Accounting" },
        { "name": "Angela Martin",  "seniority": 5, "department": "Accounting" }
    ]},
    proxy: {
        type: 'memory',
        reader: {
            type: 'json',
            root: 'employees'
        }
    }
});

Ext.create('Ext.grid.Panel', {
    title: 'Employees',
    store: Ext.data.StoreManager.lookup('employeeStore'),
    columns: [
        { text: 'Name',     dataIndex: 'name' },
        { text: 'Seniority', dataIndex: 'seniority' }
    ],
    features: [{ftype:'grouping'}],
    viewConfig: {
        plugins: {
            ptype: 'gridviewdragdrop',
            dragText: 'Drag and drop to reorganize'
        }
    },
    width: 200,
    height: 275,
    renderTo: Ext.getBody()
});