i also change the parameters for the requiredfields since in the constructor it requires array type and it's still not working
$validators = new RequiredFields( array('ID', 'Name', 'Name2', 'Email'));
Take a look at this: http://silverstripe.org/all-other-modules/show/16073
I am not 100% sure , if this will work:
$rule_MyCheckbox_Required = new NetefxValidatorRule("MyCheckbox", "REQUIRED", "", "You have to confirm this checkbox.");
If it is not working either, you can use:
$rule_MyCheckbox_Selected = new NetefxValidatorRule ("MyCheckbox", "TEXTIS", array("1"), "You have to confirm this checkbox.");
Note: What is also possible is the validation of a checkboxfieldset.
There is a build in function that lets you define the minimum number/maximum number of checkboxes that have to be checked.
(this rule is not explicitly described in the documentation. i will add example code for this next week).