Check the console of the browser and look if you see any error like: “Uncaught TypeError: undefined is not a function”. This errors means that the browser doesn’t know the Modula JavaScript plugin, most of the time the problem is caused by a wrong jQuery inclusion by the theme or another plugin.
To check for plugin incompatibilities deactivate all of your plugins for a couple of minutes except Modula to see if it works afterward. If it works once you have your plugins deactivated then re-activate them one by one until you find the culprit.
Let us know if you find incompatibilities and we'll do our best to solve them in future updates.