ASP .NET - AJAX Control Toolkit ValidatorCallout not working on edit template

Question

I have a page that has a listview that is used for inserting and editing records. Assigning a RequiredFieldValidator and ValidatorCallOutExtender to the InsertItemTemplate works well.
When I try to do the same on the EditItemTemplate the ValidatorCallOut appears but with no text in the box. Is there something that I'm doing wrong?

My code for the InsertItemTemplate:

 <asp:TextBox ID="date_timeTextBox" runat="server" Text='<%# Bind("date_time") %>' />
 <asp:RequiredFieldValidator 
      ControlToValidate="date_timeTextBox" 
      ID="RequiredFieldValidator1" 
      runat="server" 
      ErrorMessage="date_time is required" 
      Display="None" 
      ValidationGroup="insert_into">
 </asp:RequiredFieldValidator>
 <cc1:ValidatorCalloutExtender ID="ValidatorCalloutExtender1" 
      runat="server" 
      TargetControlID="RequiredFieldValidator1">
 </cc1:ValidatorCalloutExtender>

And for the EditItemTemplate:

<asp:TextBox 
    ID="date_timeTextBox" 
    runat="server" 
    Text='<%# Bind("date_time","{0:yyyy-MM-dd}") %>' />
<asp:RequiredFieldValidator 
    ControlToValidate="date_timeTextBox" 
    ID="reqDTT"       
    runat="server" 
    ErrorMessage="date_time is required" 
    Display="None" 
    ValidationGroup="edit_validate">
</asp:RequiredFieldValidator>
<cc1:ValidatorCalloutExtender 
    ID="val_reqDTT" 
    runat="server" 
    TargetControlID="reqDTT">
</cc1:ValidatorCalloutExtender>

Answer 1

Make sure your ID's are unique across your Templates, so the ControlToValidate="date_timeTextBox" is different.

InsertTemplate

 <asp:TextBox ID="date_timeTextBoxInsert" runat="server" Text='<%# Bind("date_time") %>' />

EditTemplate

 <asp:TextBox ID="date_timeTextBoxEdit" runat="server" Text='<%# Bind("date_time") %>' />