I have been having this problem for the last week. I have a persistant alarm set on my phone set for Monday through Friday. I don't really rely on it(thankfully) but last week it didn't go off on Thursday. I noticed it didn't go off Friday as well. Sunday night I went and just set the time on the alarm 15 minutes ahead. The alarm went off on Monday morning but hasn't gone off since. So it seems if I edit the alarm it will go off once but it hasn't gone off since. Before last Thursday I had never had the problem. Also just as a note I pulled the battery on the phone for a "reset" and it didn't seem to make a difference. Any ideas?