Validation Response Behavior Not Displaying

I am at a loss. I have successfully configured client side validation with a previous version of the Validation Toolkit (VT) but I cannot seem to get the validation response behavior to display for my registration form.

Here's what I use: Dreamweaver CS4; VT 2.3.5; MySQL; PHP; testing w/ IE8 and Safari.
Here is the URL: njjbareg.php

In my database, I have several fields that cannot be null. I configured VT with a validation behavior of Required as well as some other behaviors (ex. - alphanumeric). When I test the form leaving the first "required" field blank, rather than getting the alert with the header, footer, and a list of all validations that have failed, I get the following single line in the browser:

Column 'Player_First_Name' cannot be null

This is the field name from the database!

I've searched the forum and fixed several errors in the validation setup. For example, I had two form element names beginning with a number so I changed that. But I cannot find anything specific to my problem.

I can't figure out what the problem is. I am going to start from scratch (ahhh!).

Any assistance would be greatly appreciated.