Okay, we'll have to admit we've made a silly mistake with the 1.2.0 release.
As we always test our extensions in a freshly installed Joomla! but with the Debug System option to on we had missed the HitZero plugin doesn;t load jQuery correctly when Debug System is set to off. Our bad but just now we've updated the HitZero plugin for you to download. Still free to use on any of your websites ;-)
You can find a bit more information on the product page and you can download it from the HitZero download section. Ofcourse we've also created documentation for the plugin which can be found here.