Sub Category clicks close parent category

I have setup the FAQs on my site to have categories and sub categories. I am using the setting "Clicking on category opens/hides questions and answers under category". When I click on the parent category it opens exposing the sub categories, but when I click the sub categories it closes the parent category. I believe the problem stems from the fact that the JS closes all open categories when a new one is opened. It seems to be ignorant of parent/child categories. I have modified the JS to compensate for this and now it works. The patch will be added in the first comment. Also the JS could use a bit of tweaking. For instance if you use a declaration more than once in jQuery you should save it to a variable so that the browser only does one DOM lookup.
var $this = $(this);
$this.next();