Since a few weeks I have the very odd effect, that the S-II's built-in Clock app's timer does not ring, when going off. It silently displays "Time's up" on screen, but doesn't sound nor vibrate.
I do have set a sound in Clock => Timer => Menu => Settings => Alarm Tone and the volume is turned to 100%. I also have set all sounds in Home screen => Menu => Settings => Sound => Volume up to 100% but ther is not sound!
It drives me nuts and makes the device practically useless as an alert device!
PS.: I do not have any automatic task killer installed.