Ringer not working

[bnl552]

I am running Mighty 3.1 (I have had this same problem on previous releases as well, and i beleive on Juicy as well). My ringer will work just fine for a week or two and then it will just stop working. I have the volume turned all the way up but no ring. I can set it to vibrate and it will work just fine. Also, my alarm does not ring either. In fact when i set an alarm it tell me the alarm will not ring until I turn the volume on, even though it is on. Notifications however work just fine (voicemail, txt msg, etc.)

Any ideas? I was late for work because it decided to quit working over night and my alarm didn't go off!