The Notifications module has been full of bugs for some time now, we still see our users receiving 2, 4, 10 notifications for the same event from time to time. This is intermittent.

Unfortunately, despite both ourselves and many others asking for help on the notification issues there has been very little assistance from UNA, we had to bring in a third party developer to help us get notifications under control.

My advice is to turn off as many "Push" notifications as possible on your site and all "E-mail" notifications. It's the e-mails that really bug users.

Look out for the BLUE warning sign in your notifications module, this means trouble is ahead as the system is going to spam your users. Even if you clear these triangles, they come back.