Slow to select options (checkboxes)

This is a test site where I’m working on a restaurant website. You can check the product add ons under the “Salads” and “Asian Salad”. I’m adding dressings/toppings to see how this plugin works and noticed that when I check a “dressing”, there is some delay in making the selection. It looks like the page freezes up and I’m not sure why this is happening. Is there a way to speed the processing up?

The page I need help with: [log in to see the link]