RadGrid nestedview sort makes nestedview disappear?

Question

When I click on the header of my detail table, it disappears entirely, leaving empty white space in the browser where it used to be.

The Ajax postback caused by my clicking on the header does fire FooGridNeedDataSource and FooGridItemCommand, but I've used the debugger to skip the code inside those handlers (after clicking the header of the column I'm trying to sort, in the detail table), and I still get the same behavior.

I'm hoping someone can tell me what I'm doing wrong? The MasterTableView sorts just fine (my real markup enables that with AllowSorting="true" on MasterTableView).

<telerik:RadGrid ID="FooGrid" runat="server" AutoGenerateColumns="false" 
    OnNeedDataSource="FooGridNeedDataSource" OnItemCommand="FooGridItemCommand" >
    <MasterTableView ClientDataKeyNames="FooData" DataKeyNames="FooData">
        <Columns>
            <telerik:GridBoundColumn DataField="FooData" HeaderText="Foo"></telerik:GridBoundColumn>
        </Columns>
        <DetailTables>
            <telerik:GridTableView AllowSorting="true">
                <Columns>
                    <telerik:GridBoundColumn DataField="FooDetailData" HeaderText="Foo Detail" ></telerik:GridBoundColumn>
                </Columns>
            </telerik:GridTableView>
        </DetailTables>
    </MasterTableView>
</telerik:RadGrid>