ObjectDataSourc e Bind( ) on Template Column losing data on Sort

[GMartin]

I have a pop-up form with a three columned Grid that has checkboxes in
a Template Column in the first/left-most column. (The form is to
allow users to select "Members" of a group, where they check or clear
the boxes next to the potential members they want to add or remove.)

The Object Data Source is as follows...
<asp:ObjectData Source ID="odsMembers " runat="server"
SelectMethod="G etGroupMembersS electList"
TypeName="MyDat aAccessLayer.My Object">
<SelectParamete rs>
<asp:ControlPar ameter ControlID="hdnG roupSeqNo"
DefaultValue="" Name="GroupSeqN o"
PropertyName="V alue" Type="Int32" />
<asp:ControlPar ameter ControlID="hdnG roupListName"
Name="ListName" PropertyName="V alue"
Type="Object" />
</SelectParameter s>
</asp:ObjectDataS ource>

The binding to the Grid is set up like this...
<asp:GridView ID="grdGroupMem bers"
runat="server" AllowSorting="T rue" AutoGenerateCol umns="False"
Width="97%" DataSourceID="o dsMembers" DataKeyNames="M emberSeqNo">
<Columns>
<asp:TemplateFi eld
SortExpression= "Selected" >
<ItemStyle
HorizontalAlign ="Center" Width="5%" />
<HeaderStyle
HorizontalAlign ="Center" />
<ItemTemplate >
<asp:CheckBox
ID="chkSelect" runat="server" Checked=<%# Bind("SELECTED" )%/>
</ItemTemplate>
</asp:TemplateFie ld>
<asp:BoundFie ld
DataField="Memb erID" HeaderText="Mem ber" SortExpression= "MemberID">
<ItemStyle Width="35%" />
</asp:BoundField>
<asp:BoundFie ld
DataField="Memb erDescription" HeaderText="Des cription"
SortExpression= "MemberDescript ion">
<ItemStyle Width="60%" />
</asp:BoundField>
</Columns>
</asp:GridView>

The ObjectDataSourc e calls my class ok, and returns a Typed DataSet
with MemberSeqNo, MemberID, MemberDescripti on, and Selected that it
loads correctly to the GridView.popula ting the CheckBoxes. But if a
user Selects/Deselects checkmarks and then Sorts (which is likely
because the List of potential members is long) their selections are
lost, and they're hating life. ...It sorts, and returns

I either need to...
1. Have the ObjectDataSourc e Update just Prior to it sorting.
Or....
2. Bind the Template Column "correctly? " to the ObjectDataSourc e so
the values are persisted/saved correctly.

The GridView's Sorting Events aren't being triggered when bound to the
ObjectDataSourc e, so I can't catch it there. And the ObjectDataSourc e
doesn't have a Sort Event that I could find, so Option 1 is looking
unlikely.

Am I binding this wrong to work with 2-Way binding? Is there anything
anyone sees that it looks like I may be doing wrong? Does, or can the
Sort routine be set to run an Update first?

Your help is much appreciated.