GridColumn Date showing wrong date

Dear all,

I am struggling to figure out a problem related to Date.

problem 1) The date returned in the Json is 02/28/10, but when it displays in the grid, it shows it as 02/17/10 which is one less than the returned date.

problem 2) : This date does not work in IE at all, it displays it as NaN/NaN/NaN in date column.

This is how I have defined, Grid, and Store.

Grid:

Code:

 {   xtype: 'datecolumn',
                dataIndex: 'createDate',
                header: 'Create Date',
                renderer: Ext.util.Format.dateRenderer('m/d/y'),
                width: 100
 },

Store:

Code:

{
             xtype: 'datefield',
             name: 'createDate',
             dateFormat:'m/d/Y'
         },

Any help will be highly appreciated.