[Plugin: Login With Ajax] plugin not working with terms of Use

i have installed a plugin called “Terms of Use” that requires agreement to terms of use upon users registration. The “I agree” checkbox appears in the Ajax registration form but it’s not active: indeed, registration is possible even without checking it. How can I activate it? Is “Login with Ajax” compatible with Terms of Use plugin? Thanks

http://wordpress.org/extend/plugins/login-with-ajax/