Hi,
I had the same kind of problem.
Try to put the AllowAutomaticUpdates="True" (and all the others AllowAutomatic) in the MasterTableView tag.
<telerik:RadGrid ID="YourGrid" runat="server" AutoGenerateDeleteColumn="True" AutoGenerateEditColumn="True" CellSpacing="0" DataSourceID="YourEDSDataSource" GridLines="None" >
<ClientSettings>
<Selecting CellSelectionMode="None"></Selecting>
</ClientSettings>
<MasterTableView AutoGenerateColumns="False" DataKeyNames="Id" DataSourceID="YourEDSDataSource" EditMode="InPlace" AllowAutomaticUpdates="true" AllowAutomaticInserts="true" AllowAutomaticDeletes="true">
(...)
Hope it helps,
Regards
Raph