[AT&T Samsung Galaxy Note I717] taob:
Too hard to say without additional information from a logcat, or other data like that. How did you reinstall apps? Did you try to restore system-level settings, or did you restore everything manually?

---------- Post added at 08:05 PM ---------- Previous post was at 07:47 PM ----------

I just remembered I had bought DoubleTwist Alarm a while back during one of the Play Store app sales. I reinstalled it last night, set an alarm for this morning, and it worked fine. I was running a logcat at the time, and most of the entries between yours and mine are the same. But then I see this in yours:

11-24 09:23:02.038 I/ActivityManager(448): Displayed com.doubleTwist.alarmClock/.RingingScreenActivity: +1s816ms
11-24 09:23:02.288 E/AwesomePlayer(195): LPAPlayer created, LPA MODE detected mime audio/mpeg duration 277524897
11-24 09:23:02.298 E/AudioPolicyManagerBase(195): profile found: device 2, flags 1001, samplingrate 44100, format 1, channelMask 3
11-24 09:23:02.298 E/AudioTrack(195): Could not get audio output for stream type 4
11-24 09:23:02.298 E/AudioSink(195): Unable to create audio track
11-24 09:23:02.298 E/LPAPlayer(195): setupAudioSink:Audio sink open failed.
11-24 09:23:02.298 D/LPAPlayer(195): setupAudioSink:dIRECT track opened
11-24 09:23:02.298 E/LPAPlayer(195): Opening a routing session failed
11-24 09:23:02.298 E/AwesomePlayer(195): deleting Audio Player - start failed
11-24 09:23:10.236 W/ActivityManager(448): Activity idle timeout for ActivityRecord{4108d690 com.doubleTwist.alarmClock/.RingingScreenActivity}
11-24 09:23:10.476 W/ActivityManager(448): Activity stop timeout for ActivityRecord{4108d690 com.doubleTwist.alarmClock/.RingingScreenActivity}
11-24 09:23:10.476 I/ActivityManager(448): Activity reported stop, but no longer stopping: ActivityRecord{4108d690 com.doubleTwist.alarmClock/.RingingScreenActivity}

My logcat looks like this, starting at the same event:

11-25 09:00:00.612 I/AlarmStore(26918): =================================
11-25 09:00:00.612 I/AlarmStore(26918): = SCHEDULED FOR
11-25 09:00:00.612 I/AlarmStore(26918): = 12/1/12 9:00 AM
11-25 09:00:00.612 I/AlarmStore(26918): = (1354370400000)
11-25 09:00:00.612 I/AlarmStore(26918): =================================
11-25 09:00:01.073 W/ActivityManager( 448): Activity pause timeout for ActivityRecord{41035ed0 com.doubleTwist.alarmClock/.RingingScreenActivity}
11-25 09:00:02.104 I/ActivityManager( 448): Activity reported stop, but no longer stopping: ActivityRecord{41035ed0 com.doubleTwist.alarmClock/.RingingScreenActivity}
11-25 09:00:02.794 I/ActivityManager( 448): Start proc com.android.deskclock for broadcast com.android.deskclock/com.android.alarmclock.AnalogAppWidgetProvider: pid=27030 uid=10142 gids={1028}
11-25 09:00:02.924 I/ActivityThread(27030): Pub com.android.deskclock: com.android.deskclock.AlarmProvider
11-25 09:00:03.915 I/ActivityManager( 448): Displayed com.doubleTwist.alarmClock/.RingingScreenActivity: +3s344ms

I don't have anything about AwesomePlayer or LPAPlayer, etc. Any idea what those are? What category of alarm sound are you using with DoubleTwist? Mine is set to "Sound", and I'm playing an OGG file. Is yours set to "Song" and playing an MP3? Maybe try a sound instead of a song, and see if MP3 vs OGG makes a difference.