I have installed the testimonials widget on a demo site for the client, and it is working perfectly. Now I'm building the client's site, and the widget not only doesn't appear, it stops the rest of the HTML from loading. When I look at the HTML source code, it stops at the end of the last widget before the testimonials widget HTML should appear, i.e. the rest of the sidebar code as well as the footer code and the </html> closing tag is missing.
I am using the same version of WordPress and theme on both sites. There is no duplicate jquery.js in the theme or anywhere else. Any ideas?