Formview disappearing on 2nd postback

OK here's my page design... there is a DataList with a "Select" imagebutton. When it is clicked, that item is loaded into a FormView in Edit mode for changes. When the page loads, selecting the first item works fine. However if I click another item's select button, the FormView simply disappears. Some code...

The Page

<div id="Left">
    <asp:DataList ID="UsersDataList" runat="server" DataKeyField="UserID" OnSelectedIndexChanged="UsersDataList_SelectedIndexChanged" 
        OnDeleteCommand="UsersDataList_DeleteCommand" RepeatLayout="Flow">
        <ItemTemplate>
            <span><%#Eval("FirstName") %> <%#Eval("LastName") %></span>
            <asp:ImageButton ID="EditImageButton" runat="server" ImageUrl="~/Images/EditIcon.gif" AlternateText="Edit" 
                CommandName="Select" CommandArgument='<%#Eval("UserId") %>' />
            <hr />
        </ItemTemplate>
    </asp:DataList>
</div>

<div id="Right">
    <asp:FormView ID="UserFormView" runat="server" DefaultMode="Insert" OnItemCommand="UserFormView_ItemCommand" 
        OnItemInserting="UserFormView_ItemInserting">
        <InsertItemTemplate>
            <asp:Label ID="LoginNameLabel" runat="server" Text="Login Name" CssClass="Label" AssociatedControlID="LoginNameTextBox" />
            <asp:TextBox ID="LoginNameTextBox" runat="server" MaxLength="30" CssClass="TextBox" />

            <asp:Button ID="AddButton" runat="server" Text="Add User" CommandName="Insert" CssClass="Button" />
            <asp:Button ID="ClearButton" runat="server" Text="Clear" CommandName="Cancel" CssClass="Button" />
        </InsertItemTemplate>
        <EditItemTemplate>
            <asp:Label ID="LoginNameLabel" runat="server" Text="Login Name" CssClass="Label" AssociatedControlID="LoginNameTextBox" />
            <asp:TextBox ID="LoginNameTextBox" runat="server" MaxLength="30" CssClass="TextBox" />

            <asp:Button ID="UpdateButton" runat="server" Text="Update User" CommandName="Update" CssClass="Button" />
            <asp:Button ID="DeleteButton" runat="server" Text="Delete User" CommandName="Delete" CssClass="Button" />
            <asp:Button ID="CancelButton" runat="server" Text="Cancel" CommandName="Cancel" CssClass="Button" />
        </EditItemTemplate>
    </asp:FormView>
</div>

And the code behind...

protected void UsersDataList_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (UserFormView.CurrentMode != FormViewMode.Edit)
        {
            UserFormView.ChangeMode(FormViewMode.Edit);
        }

        this.LoadUser(Convert.ToInt32((sender as DataList).SelectedValue));
    }

private void LoadUser(int userId)
    {
        // Some code to get the "user" object from the userId

        ((TextBox)UserFormView.FindControl("LoginNameTextBox")).Text = user.LoginName;
    }

The last line of the LoadUser routine throws a null reference exception the 2nd time around of course. If I comment the line out the page loads but the FormView has disappeared. Please help!

ansaurus

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Formview disappearing on 2nd postback

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