[Plugin: Optima Express IDX Plugin] Theme compatibility?

I’m certainly interested in the plugin. I saw the demo and I was impressed. I’ve setup a trial account, added the registration code to the plugin settings, but all the pages show the same empty page: http://www.kathyrawls.com/homes-for-sale-search/

This is a pretty bare bones WP install. A gantry-framework powered theme from rockethemes, and a few plugins, but that’s it. How common are theme incompatibilities with this plugin? and is that what I’m seeing here?

http://ww.wp.xz.cn/extend/plugins/optima-express/