Twice this year (2013) I have realized that I am not receiving anticipated notifications for events I have scheduled and set up three such notifications (1 week  before, 2 days before, and 1 day before). The previous instance was around the April time frame and when I started checking the notification schedule the three schedule slots were still in place but all had been reset to 15 mins. Today when I start checking, they have all been reset to 12 hours. Can anyone tell me what is going on and how to avoid this - it is really frustrating having to edit all my entries to correct them - not to mention short notice on events I anticipated would be flagged a week ahead of time.