Since Firefox 18 was released, new users have been unable to register on our Joomla-based site. The form loads and works in Chrome, IE, and Firefox 17 but not Firefox 18. To make things even more confusing: Inspect Element in Firefox 18 shows a form element that is empty, however, View Page Source in Firefox 18 shows the entire form. Furthermore, using the Web Developer Tools, we checked the HTTP request and response. The response contains the entire form (including inner elements) but Firefox 18 and Inspect Element still don't show these. We've tried dumping the cache, installing the latest Java update, and resetting Firefox to default (i.e. no add-ons or themes.) We are completely stumped on what to do. We've put in a support request, but we're wondering if anyone else has any idea what could be the problem.
Here's the site for reference: SIJHSAA -- if you click on "Create an account" in the right hand sidebar, this is the form that is not working in Firefox 18.