Weird behaviour clientside validation with Image captcha module!

Hi,

In drupal's default register form I added two extra fields with 'First Name','Last Name' and Image captcha module.Everything is fine when users leave field blank means validated.But in the scenario like user fills the username field and then Image captcha field with incorrect or correct input and presses the create new account button then other fields validation error do not show up means email,first name and last name fields validation do not show up and form is not submitting.Then if you press the button again then it will show up means you have to press the button twice.If I disable image captcha for the form it performs correctly.Is that a issue with clientside validation module?