Hey,
You guys have a nice looking site! Also good job getting the AJAX links working. They all seem to work fine for me in Chrome. While AJAX links might make the content load faster and make for a more seamless browsing experience, there are a few downsides to this approach that make it generally discouraged.
#1 was already mentioned, which is it causes the browser back button to become non functional. As was posted, there are work arounds for this.
#2 is that it negatively affects search engine indexing. The google crawler does not know how to crawl AJAX links. One way around this is to use a technique called progressive enhancement. For example, have all your links be in the normal <a href="URL"> format, and then have javascript that goes and binds the necessary events for turning those into pages loaded over AJAX. This means that you still need to have those pages exist at a real URL location. If you are using a content management system, this is a pretty easy tasks to accomplish. This will still allow the search engine crawlers (which have no javascript interpreting) to crawl and index all of those pages.
Just a few things to keep in mind and to weight against the benefits. PM me if you would like any more information on how to implement these
