Error notification doesn't append the version of the plugin to the .js file include, which for us with CDNs or enforcing browser caching means an old copy will be served upon an upgrade for a potentially long time.
Take a look at http://www.androidpolice.com/2013/06/21/new-game-gameloft-releases-gangstar-vegas-their-most-gta-like-gta-clone-yet-for-6-99/, for example. All other plugins version their .js files by appending ?ver=N.NN, whereas yours doesn't. From what I can tell, the problem is you're not passing the version here:
wp_register_script('error_notification_script', plugins_url('/error_notification.js', __FILE__), null, null, true);