Custom rule into jQ.validate's 'rules' obj breaks validation on submit

Custom rule into jQ.validate's 'rules' obj breaks validation on submit

When I add a custom validator to the jQuery validator's rules collection, it breaks the validation that is supposed to happen when I click the submit button.

When the submit button is clicked and no form item, input nor select has been visited (made active, then blurred), the submit handler doesn't catch the validation errors and shows no error messages, but submits the form instead.

If I remove the custom rule, it works, i.e. if I remove lines 4-12 inclusive, in listing 1, the error messages for the required fields are triggered and shown.

I have this code (listing 1):
  1. $("#mpForm").validate({
  2.     debug : true,
  3.     rules : {
  4.         'time_down' : {
  5.             'greaterThan' : [{
  6.                 type : 'datetime',
  7.                 firstDate : $('#date_up'),
  8.                 firstTime : $('#time_up'),
  9.                 secondDate: $('#date_down'),
  10.                 secondTime: $('#time_down')
  11.             }, 'Time Up']
  12.         }
  13.     }
  14. });
And in the actual form, three required elements:
  1. <tr>
  2.     <th><label for="namn"><%= Me.Text("Number")%></label></th>
  3.     <td><input type="text" name="namn" id="namn" size="30" class="required" maxlength="30" value="<%= matpunkt.namn.SafeAttribute() %>" /></td>
  4. </tr>
and a slew of optional but validated fields.

The custom validation method is added as such:
  1. /**
  2.      * greaterThan :: String -> HtmlNode -> Array[ 0: OptionsObject, 1: "Nice name of the node/nodes" ]
  3.      */
  4.     jQuery.validator.addMethod("greaterThan", function(value, element, params) {
  5.         var $F = Date.CultureInfo.formatPatterns;
  6. ...
  7.     }
I've spent A LOT of time trying to make this work. It's just isn't working out for me. I appreciate any suggestions for solutions.

Regards