[jQuery] [validate] Password validation works in FF3 but not in IE6

[dk]

Thanks for a great validation plugin!

Writing my first custom validation:

<script>
      $(document).ready(function(){
        jQuery.validator.addMethod("adminPwd", function(value,
element) {
            return this.optional(element) || /^(?=.*\d)(?=.*[a-z])(?
=.*[A-Z])(?!.*\s)(?!.*\W).{8,255}$/.test(value);
        }, "The password must contain lower case, upper case and
number(s) and be at least 8 characters");
        $('#userForm').validate();
      });
</script>

The aim is that the password must contain at least one lower case, one
upper case and one number. Spaces are not allowed. Lenght at least 8
characters

This works in FF3 but not in IE6. I suspect some regular expression
incompability in IE6 but I don't know how to debug it to pinpoint
exactly which part of the RE fails.

Any workarounds would be appretiated!

dk