Hi, just joined to say I'm having this same problem. I never had this problem until upgrading to 2.1. I have my clock process excluded in my task manager, I check the volume level every night through Audio Manager, and even in the clock app - and it is not going off. I set alarms for everything, so this is very frustrating. I can set a test alarm for two minutes from now and it will go off with no issues at full volume. But if I leave it alone for awhile, the alarm won't go off. I think the most reasonable thing to assume here is that it has something to do with the clock not updating until you turn the phone on. I don't know what to do.