GridView-generated code adds "width='100%'" to the table it creates

My page looks correct in Firefox and IE8. But in IE7, a nested gridview spills into the adjacent cell, much like the issue here.

Looking at it in the developer tools, there is an inline-style associated with the table that ASP.NET generated, and it has a width attribute of 100%. If I remove this, the nested table pops back where it belongs.

Problem is, nowhere is an inline-style set. In fact, if I try to set width='250px', it gets overridden with width='100%'. If I try to remove the width attribute in the code-behind, attrGridView.Attributes["Width"] is null, and calling .Remove() does nothing. But every asp.net-generated gridview-table has an inline style with width='100%' set on it (it's only causing me issues in one place).

Setting table-layout='fixed', as suggested in the article I linked to, did not help.

How do I get ASP.NET to stop setting this property?

Some code:

<asp:TemplateField HeaderText="Attributes" SortExpression="Attributes">
  <HeaderStyle CssClass="GridHeaderCell" />
  <ItemStyle CssClass="GridTableCell AttrGridCellPadding" />
  <ItemTemplate>

    <asp:GridView id="attributesGridView" runat="server"
         AutoGenerateColumns="false" ShowHeader="false" GridLines="None" 
         AlternatingRowStyle-BackColor="White" CssClass="StupidGridView" > 

      <EmptyDataTemplate>
        <p class="italic">There are no attributes for this request.</p>
      </EmptyDataTemplate>

      <Columns>
        <asp:TemplateField>
          <ItemStyle CssClass="AttrTableCell" />
          <ItemTemplate>
            <asp:Label id="attributeName" runat="server" 
                 Text='<%# Eval("Name") + ":&nbsp;&nbsp; "+ Eval("Value") %>'
                 CssClass="AttrGridCell"></asp:Label>
          </ItemTemplate>
        </asp:TemplateField>
      </Columns>

    </asp:GridView>
  </ItemTemplate>
</asp:TemplateField>


.StupidGridView {
  width:  250px;
}

Solution

Themes are being applied and overriding control-level settings. Check theme settings on page, web.config, or anywhere else a theme may be set.