Created Unassigned: Incorrect Validation Message in Callout Extender [27922]

All of the callouts on my page just display the message "Control is not valid." I am not doing anything out of the ordinary, and here is a sample of how they are set up (Note that they are in a Modal popup):

```
<asp:TextBox ID="retrieveEmailFirstNameTextBox" runat="server" MaxLength="50" />
<asp:RequiredFieldValidator runat="server" ID="retrieveEmailFirstNameTextBoxRequiredFieldValidator" Text="Please enter your first name to proceed." ControlToValidate="retrieveEmailFirstNameTextBox" />
<asp:ValidatorCalloutExtender ID="retrieveEmailFirstNameTextBoxRequiredFieldValidatorCalloutExtender" TargetControlID="retrieveEmailFirstNameTextBoxRequiredFieldValidator" runat="server"></asp:ValidatorCalloutExtender>

```
Image showing behavior is attached.

I am using the latest version of the toolkit.