Yes, there has been conflict with jQuery UI Tabs and the jQueryTools library that the theme uses for the slider. This have been fixed in the latest development version though, and will be available in the next update.
However, the Post UI Tabs plugin itself has an issue in that it’s trying to load a stylesheet file for the tabs from Google’s server, which returns a 404 Not Found error. So even though there is no conflict with the theme, the plugin will still not work because of this.
I’ve tried several tabs plugin in the course of investigating this issue, and found that the WP UI plugin is the the best one if you’re looking for the tabs functionality.