I have a Grid with json Store and a DateField. Firefox ist working good, but its not working in Internet Explorer 8. 

I define it like this:

```
function convert(v, rec) {
    var value;
    Ext.isEmpty(v) ? value = '' : value = v;
    return value;
}

fields : [                      
    {name: 'date1', type: 'date', dateFormat: 'Y-m-d', convert: convert},
    {name: 'date2', type: 'date', dateFormat: 'Y-m-d', convert: convert},
]

```

In Firefox it look good, but in Internet Explorer it is only `NaN.NaN.NaN`