Repeater inside another control

I am using Telerik AJAX controls and I have a little problem. In my application, the user enters the number of "weeks", and then the program dynamically adds RadPane to the repeater (with a separator so they can resize), with RadGrid inside the panels.

I have the following markup:

<telerik:RadSplitter ID="splt" runat="server" Width="100%">              
<asp:Repeater ID="rptSplitter" runat="server" OnItemDataBound="rptSplitter_ItemDataBound">
<ItemTemplate>
<telerik:RadPane ID="pane" runat="server">
<asp:Label ID="lblText" runat="server" Text='<%# DataBinder.Eval(Container.DataItem,"From") %>'></asp:Label>
<telerik:RadGrid ID="gv" runat="server" AutoGenerateColumns="false">
<MasterTableView runat="server" DataKeyNames="ID">
<Columns>
<telerik:GridBoundColumn DataField="ConsignmentNo" HeaderText="Consignment" SortExpression="ConsignmentNo">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="Customer" HeaderText="Customer" SortExpression="Customer"></telerik:GridBoundColumn>
</Columns>
</MasterTableView>
</telerik:RadGrid>
</telerik:RadPane>
</ItemTemplate>
<SeparatorTemplate>
<telerik:RadSplitBar runat="server"></telerik:RadSplitBar>
</SeparatorTemplate>
</asp:Repeater>
</telerik:RadSplitter>

When linking the repeater, however, I get the following exception (well, the exception is not displayed, but I can "see" it in the itemdatabound event of the grid):

"RadPane must be placed inside the RadSplitter control."

Any ideas on how I can somehow make this work?