Update: I've released a hotfix that should address the issue described in my previous post.
I'm unable to replicate any issues with AJAX Threads (beyond the above) on your site - I still see all AJAX requests to fetch new posts go off as intended.
That being said, the file: /dbtech/vbslider/clientscript/jquery.mobile.customized.min.js?v=300b1 on your server has a JS error. This is due to an issue with our server-side JS minifier over-minifying that file.
I've corrected that issue as well.
Re-downloading and re-uploading AJAX Threads and vBSlider should fix these issues for you