During page load we set the the DataValue and DisplayValue of the contorl. There is also an attached datasouceid to the control which acutally is getting triggered after he assign. When the data souce gets triggered it destroys the the value in the DataValue propery. Below is control snip and the object datasouce snip i am using. the code behind the ods is a simple datatable.

<IG:WebCombo ID="wcGroup" runat="server" Width="100%" IAName="GroupCode" DropDownLayout-AutoGenerateColumns="false" DataTextField="GroupCode" DataValueField="GroupId" EnableXmlHTTP="True" Editable="True" ComboTypeAhead="Suggest" DataSourceID="odcGroup" />

 <ASP:ObjectDataSource ID="odcGroup" runat="server" TypeName="InterAmerica.CapCorr.Application.Controls.UserPreferences.UserPreferencesBase" SelectMethod="GetGroupCode"><SelectParameters><asp:ControlParameter ControlID="wcGroup" Name="groupCode" PropertyName="DisplayValue" /></SelectParameters>
</IA:ObjectDataSource>