Gridview Styling Not Rendering

Why is the following asp.net code not including styling information when being rendered to HTML?

<asp:GridView ID="GridView1" runat="server" CellPadding="4" ForeColor="#333333"
GridLines="None">
<RowStyle BackColor="#FFFBD6" ForeColor="#333333" />
<FooterStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#FFCC66" ForeColor="#333333" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="Navy" />
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="White" />
<AlternatingRowStyle BackColor="White" />
</asp:GridView>
Here is the HTML that is rendered:
<div class="AspNet-GridView" id="GridView1">
<table cellpadding="0" cellspacing="0" summary="">
<thead>
<tr>
<th scope="col">Name</th>
<th scope="col">Age</th>
<th scope="col">Sex</th>
</tr>
</thead>
<tbody>
<tr>
<td>Ronnie</td>
<td>25</td>
<td>M</td>
</tr>
<tr class="AspNet-GridView-Alternate">
<td>Tina</td>
<td>25</td>
<td>F</td>
</tr>
<tr>
<td>Lukus</td>
<td>4</td>
<td>M</td>
</tr>
</tbody>
</table>
</div>

There are no themes defined for this site. Any ideas what is going on? EDIT I created a new web site in VWD Express and copy and pasted my gridview code, which resulting in the following HTML being rendered:

<div>
<table cellspacing="0" cellpadding="4" border="0" id="GridView1" style="color:#333333;border-collapse:collapse;">
<tr style="color:White;background-color:#990000;font-weight:bold;">
<th scope="col">Name</th><th scope="col">Age</th><th scope="col">Sex</th>
</tr><tr style="color:#333333;background-color:#FFFBD6;">
<td>Ronnie</td><td>25</td><td>M</td>
</tr><tr style="color:#333333;background-color:White;">
<td>Tina</td><td>25</td><td>F</td>
</tr><tr style="color:#333333;background-color:#FFFBD6;">
<td>Lukus</td><td>4</td><td>M</td>
</tr>
</table>
</div>

Something is keeping styling information from being included in my original project.