Issues with GridView in ASP.NET 2.0

Please share all the issues with GridView in ASP.NET 2.0 under this thread.

I have a very serious problem working with GridView.
I'm trying to use DirectoryInfo to retrieve file information to display in the GridView and this works fine...

Now I was to sort (Ascending & Descending) the files on click of Cloumn click...

But now since GridView has inbuilt sorting, was tying to use the same... And I faced 2 issues while doing so...
Below is all the details with the code:

ASPX Code:
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="GridView1" AllowSorting="true" runat="server" AutoGenerateColumns="False" OnSorting="GridView1_Sorting">
<Columns>
<asp:BoundField HeaderText="Full Name" DataField="Name" SortExpression="Name" />
<asp:BoundField HeaderText="Last Write Time" DataField="LastWriteTime" SortExpression="LastWriteTime" />
<asp:BoundField HeaderText="File Size" DataField="Length" SortExpression="Length" DataFormatString="{0:#,### bytes}"/>
<asp:BoundField HeaderText="Last Access Time" DataField="LastAccessTime" SortExpression="LastAccessTime" />
</Columns>
</asp:GridView>
</div>
</form>
</body>

Issue 1:
Earlier I did not have OnSorting="GridView1_Sorting" attribute and that time I received "Gridview fired event Sorting which wasn't handled." error for which I added OnSorting="GridView1_Sorting and a code behind code.

Issue 2:
After I inserted GridView1_Sorting(object sender, GridViewSortEventArgs e) in aspx.cs file,

void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
GridView1.Sort (e.SortExpression, e.SortDirection);
GridView1.DataSource = fileInfoArray;
GridView1.DataBind();
}
This code goes into Infinite Loop and when I tried to search something on the internet I found one more piece of code...i.e.
protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
DataTable m_DataTable = GridView1.DataSource as DataTable;

if (m_DataTable != null)
{
DataView m_DataView = new DataView(m_DataTable);
m_DataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);

GridView1.DataSource = m_DataView;
GridView1.DataBind();
}
}

But the problem in this code is...
DataTable m_DataTable = GridView1.DataSource as DataTable;
Retuns me a NULL Datatable.

I would be looking for all kind of help and pointers to fix this problem...

Thanks in Advance,
J.S.