There should be no functional difference for Shipping Estimator. Are you sure they were working before? What specifically is "not working" now?
Maybe you need to start a new thread about that problem unless you are absolutely certain that the new module is the cause ... in which case you'll need to also post all the relevant details such as your Zen Cart version, which versions you've upgraded from, a detailed list of all addons and mods, as well as the customizations you've made to your site, your URL, details about the kinds of quotes that are failing (intl/domestic, zip from, zip to, weight, value, etc), exact steps to reproduce the problem, etc.