RadiobuttonList inside gridview updates but doesnt show the update?
===

I've got a gridview (asp.net) with a checkbox and a radiobuttonlist.
Above this gridview I have a button that allows the user to set all SELECTED items
in the gridview to a particular value.  What I mean by selected is that checkbox that is inside the gridview is checked.  This gridview is inside an updatepanel and I dont know if this is the reason I am having an issue but here is my issue.

The gridview as I said has a checkbox like so:

     <ItemTemplate>
      <asp:CheckBox ID="chkSelector" runat="server" 
        ToolTip="Select row?" />
     </ItemTemplate>

And a radiobutton list like so:

     <asp:RadioButtonList ToolTip="Please provide an answer to the method." AutoPostBack="true" RepeatDirection="Horizontal" ID="rbAnswer" runat="server" SelectedValue='<%# DataBinder.Eval(Container, "DataItem.AnswerID")%>' OnSelectedIndexChanged="rbAnswer_SelectedIndexChanged">
                                        <asp:ListItem Text="Yes" Value="Yes" style="color:green;"></asp:ListItem>
                                        <asp:ListItem Text="No" Value="No" style="color:red;"></asp:ListItem>
                                        <asp:ListItem Text="N/A" Value="N/A" style="color:gray;"></asp:ListItem>
                                        <asp:ListItem Value="" Text="" style="display: none" />
                                    </asp:RadioButtonList>

When you check the checkbox (you can select multiple checkbox (line items in the grid) and then click this button.  The button does something to this effect:

    foreach (GridViewRow Row in this.gvLineItems.Rows)
                    {
                        CheckBox cb = (CheckBox)Row.FindControl("chkSelector");
                        Label id = (Label)Row.FindControl("lblID");
                        if (cb != null && cb.Checked)
                        {
                            long lID = Convert.ToInt32(gvLineItems.DataKeys[Row.RowIndex].Value);
                            RadioButtonList rbl = (RadioButtonList)Row.FindControl("rbAnswer");
    
                            rbl.Items.FindByText("N/A").Selected = true;
                        }
                    }

That is it loops through all items in the gridview.  If the item is checked (chkSelector = true) then it sets the radiobutton list answer to "N/A".  I debug the code and I can see the answer is set correctly but then when my method is done the User Interface doesnt show the result.  Meaning the answer was never set to N/A.  It just maintains its original state...

Does anyone know why this is happening?  I am using an updatepanel around this so I am not sure if that is the reason
???