I don't think its a conflict. In the console I'm getting this error:
jquery.min.js?a0500d9fcf682506049dbe53f0b8b433:4 POST http://bellmoresteel.com/modules/mod_s5_contact_popup/tmpl/ajax.php 404 (Not Found)
If you have site cache enabled via the Yootheme template or another plugin try disabling this. Also make sure that the ajax.php file is located at the above URL. Maybe this file is just missing.