My dad is having this problem. I haven't had it, but I don't use the alarm and timer near as much as he does.
When an alarm or timer goes off on his phone, many times he doesn't get the "Slide to Stop Alarm" or "Slide to Stop Timer" controls. Also, many times, alarms don't snooze when he tells them to. Deleting and resetting the alarms fixes the problem for a day or two, but then the problem comes back. Is anyone else experiencing this problem?