Error with automatic delete when RadGrid is bound to EntityDataSource - radgrid

Question

I have a RadGrid that's bound to EntityDataSource. A few of the columns are bound to navigation properties of the bound entity. When I try to delete a record, it gives the following error:
Error: Sys.WebForms.PageRequestManagerServerErrorException: A property named 'Vehicle.VehicleNo' was not found on the entity during an insert, update, or delete operation. Check to ensure that properties specified as binding expressions are available to the data source.
I know if I choose to use the plain foreign key IDs, instead of the navigation properties, everything works. I can easily get the delete to work if I handle it manually. But I"m just thinking there's got to be a way for the automatic delete to work too. Any ideas?
<telerik:RadGrid ID="RadGrid1" runat="server" AllowAutomaticDeletes="True"
AllowFilteringByColumn="True" AllowPaging="True" AllowSorting="True" AutoGenerateColumns="False"
DataSourceID="EntityDataSource1" GridLines="None" ShowGroupPanel="True" Skin="Hay"
OnItemUpdated="RadGrid1_ItemUpdated"
OnItemInserted="RadGrid1_ItemInserted" OnItemCommand="RadGrid1_ItemCommand"
Height="400px" Width="700px" CellSpacing="0">
<MasterTableView DataKeyNames="ADChecklistId" DataSourceID="EntityDataSource1" CommandItemDisplay="Top">
<CommandItemSettings AddNewRecordText="Add New Aerial Device Checklist" ShowRefreshButton="false"
ShowAddNewRecordButton="true"></CommandItemSettings>
<RowIndicatorColumn FilterControlAltText="Filter RowIndicator column">
<HeaderStyle Width="20px" />
</RowIndicatorColumn>
<ExpandCollapseColumn FilterControlAltText="Filter ExpandColumn column">
<HeaderStyle Width="20px" />
</ExpandCollapseColumn>
<Columns>
<telerik:GridEditCommandColumn ButtonType="ImageButton" UniqueName="EditCommandColumn"
HeaderText="Edit">
</telerik:GridEditCommandColumn>
<telerik:GridButtonColumn ButtonType="ImageButton" CommandName="Delete" UniqueName="DeleteCommandColumn" HeaderText="Delete" ConfirmDialogType="RadWindow" ConfirmText="Are you sure you want to delete this record?">
</telerik:GridButtonColumn>
<telerik:GridBoundColumn DataField="Vehicle.VehicleNo" FilterControlAltText="Filter VehicleNo column"
HeaderText="VehicleNo" SortExpression="Vehicle.VehicleNo" UniqueName="Vehicle.VehicleNo">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="Employee.FirstName" FilterControlAltText="Filter FirstName column"
HeaderText="FirstName" SortExpression="Employee.FirstName" UniqueName="Employee.FirstName">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="Employee.LastName" FilterControlAltText="Filter LastName column"
HeaderText="LastName" SortExpression="Employee.LastName" UniqueName="Employee.LastName">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn DataField="Utility.UtilityName" HeaderText="Utility" SortExpression="Utility.UtilityName" UniqueName="Utility.UtilityName" >
</telerik:GridBoundColumn>
<telerik:GridDateTimeColumn DataField="CreatedOn" DataType="System.DateTime" FilterControlAltText="Filter CreatedOn column"
HeaderText="CreatedOn" SortExpression="CreatedOn" UniqueName="CreatedOn" DataFormatString="{0:MM/dd/yy}">
</telerik:GridDateTimeColumn>
<telerik:GridBoundColumn DataField="CreatedBy" FilterControlAltText="Filter CreatedBy column"
HeaderText="CreatedBy" SortExpression="CreatedBy" UniqueName="CreatedBy">
</telerik:GridBoundColumn>
<telerik:GridDateTimeColumn DataField="ModifiedOn" DataType="System.DateTime" FilterControlAltText="Filter ModifiedOn column"
HeaderText="ModifiedOn" SortExpression="ModifiedOn" UniqueName="ModifiedOn" DataFormatString="{0:MM/dd/yy}">
</telerik:GridDateTimeColumn>
<telerik:GridBoundColumn DataField="ModifiedBy" FilterControlAltText="Filter ModifiedBy column"
HeaderText="ModifiedBy" SortExpression="ModifiedBy" UniqueName="ModifiedBy">
</telerik:GridBoundColumn>
</Columns>
<EditFormSettings>
<EditColumn FilterControlAltText="Filter EditCommandColumn column">
</EditColumn>
</EditFormSettings>
</MasterTableView>
<ClientSettings AllowDragToGroup="True" EnablePostBackOnRowClick="true">
<Scrolling AllowScroll="True" UseStaticHeaders="True" />
<Resizing AllowColumnResize="true" ClipCellContentOnResize="false" />
</ClientSettings>
<FilterMenu EnableImageSprites="False">
</FilterMenu>
<HeaderContextMenu CssClass="GridContextMenu GridContextMenu_Default">
</HeaderContextMenu>
</telerik:RadGrid>
<asp:EntityDataSource ID="EntityDataSource1" runat="server" AutoGenerateWhereClause="True"
ConnectionString="name=MSOpsEntities" DefaultContainerName="MSOpsEntities"
EnableFlattening="False" EnableDelete="True" EntitySetName="ADChecklists"
Include="Vehicle, Employee, Utility" OrderBy="it.CreatedOn DESC"
OnSelecting="EntityDataSource1_Selecting"
ondeleting="EntityDataSource1_Deleting">
<WhereParameters>
<asp:SessionParameter Name="UtilityId" SessionField="utilityId" Type="Int32" />
</WhereParameters>
</asp:EntityDataSource>

Answer 1

Try setting ReadOnly="true" on the GridBoundColumns containing the navigation properties, this worked for me. Maybe also you could use template columns with Eval rather than Bind