I am sending a copy of the WAFV_Required_C.js file that should address the error.
Please copy it to the following location:
Win Vista:
C:Users\<Your User Name>\AppData\Roaming\Adobe\Dreamweaver 9\Configuration\Behaviors\Actions\WA Validation Toolkit\Apply Client Validations
WinXP:
C:\Documents and Settings\<Your User Name>\Application Data\Adobe\Dreamweaver 9\Configuration\Behaviors\Actions\WA Validation Toolkit\Apply Client Validations