Excel 2007 : Insert row while sheet is protected

I use the following Macro for inserting row

Sub Insert_Row()
    With ActiveCell.EntireRow
        If .Row <> 1 Then
            .Offset(-1).Copy
            .Insert
            On Error Resume Next
            .Offset(-1).SpecialCells(xlCellTypeConstants).ClearContents
        End If
    End With
End Sub

Than I protect my sheet with password but allowing to insert rows.
Though it doesn't allow me to do so and get following error in macro with "insert" marked in yellow

Sub Insert_Row()
    With ActiveCell.EntireRow
        If .Row <> 1 Then
            .Offset(-1).Copy
           .Insert
            On Error Resume Next
            .Offset(-1).SpecialCells(xlCellTypeConstants).ClearContents
        End If
    End With
End Sub

How can I insert row to a sheet that is protected with password?