Rated 3 out of 5 stars
If there's an update and you click on the notification popup which loads the updated webpage it won't check for updates again unless you click the triangle on the status bar. It should reset itself when you open the webpage and re-check for updates without the need to click anything. I can't find a way to change this.This review is for a previous version of the add-on (0.12.1.1-signed.1-signed).
By enabling "Scan known pages on visit" in the settings, you get exactly the behaviour you describe.