[Xperia Arc Themes and Apps] Daniel D.:
I tried the lockscreen & settings mod but I got a bootloop. I used the Auto APK Tool 2.0.4a as you wrote in the OPs.

04-06 18:37:26.062: E/System(332): ******************************************
04-06 18:37:26.062: E/System(332): ************ Failure starting core service
04-06 18:37:26.062: E/System(332): java.lang.NullPointerException
04-06 18:37:26.062: E/System(332):	at com.android.server.pm.PackageManagerService.grantPermissionsLPw(PackageManagerService.java:4242)
04-06 18:37:26.062: E/System(332):	at com.android.server.pm.PackageManagerService.updatePermissionsLPw(PackageManagerService.java:4191)
04-06 18:37:26.062: E/System(332):	at com.android.server.pm.PackageManagerService.<init>(PackageManagerService.java:1146)
04-06 18:37:26.062: E/System(332):	at com.android.server.pm.PackageManagerService.main(PackageManagerService.java:837)
04-06 18:37:26.062: E/System(332):	at com.android.server.ServerThread.run(SystemServer.java:167)
04-06 18:37:26.062: I/SystemServer(332): Input Method Service
04-06 18:37:26.072: A/SystemServer(332): BOOT FAILURE starting Input Manager Service
04-06 18:37:26.072: A/SystemServer(332): java.lang.NullPointerException
04-06 18:37:26.072: A/SystemServer(332):	at android.app.PendingIntent.getBroadcast(PendingIntent.java:299)
04-06 18:37:26.072: A/SystemServer(332):	at com.android.server.InputMethodManagerService.<init>(InputMethodManagerService.java:552)
04-06 18:37:26.072: A/SystemServer(332):	at com.android.server.ServerThread.run(SystemServer.java:271)
04-06 18:37:26.072: W/SystemServer(332): ***********************************************
04-06 18:37:26.072: E/AndroidRuntime(332): Error reporting WTF
04-06 18:37:26.072: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.072: E/AndroidRuntime(332):	at com.android.internal.os.RuntimeInit.wtf(RuntimeInit.java:384)
04-06 18:37:26.072: E/AndroidRuntime(332):	at android.util.Log$1.onTerribleFailure(Log.java:103)
04-06 18:37:26.072: E/AndroidRuntime(332):	at android.util.Log.wtf(Log.java:278)
04-06 18:37:26.072: E/AndroidRuntime(332):	at com.android.server.ServerThread.reportWtf(SystemServer.java:78)
04-06 18:37:26.072: E/AndroidRuntime(332):	at com.android.server.ServerThread.run(SystemServer.java:274)
04-06 18:37:26.072: I/SystemServer(332): Accessibility Manager
04-06 18:37:26.072: W/SystemServer(332): ***********************************************
04-06 18:37:26.082: A/SystemServer(332): BOOT FAILURE starting Accessibility Manager
04-06 18:37:26.082: A/SystemServer(332): java.lang.NullPointerException
04-06 18:37:26.082: A/SystemServer(332):	at android.app.ContextImpl.registerReceiverInternal(ContextImpl.java:1055)
04-06 18:37:26.082: A/SystemServer(332):	at android.app.ContextImpl.registerReceiver(ContextImpl.java:1030)
04-06 18:37:26.082: A/SystemServer(332):	at android.app.ContextImpl.registerReceiver(ContextImpl.java:1024)
04-06 18:37:26.082: A/SystemServer(332):	at com.android.internal.content.PackageMonitor.register(PackageMonitor.java:65)
04-06 18:37:26.082: A/SystemServer(332):	at com.android.server.accessibility.AccessibilityManagerService.registerPackageChangeAndBootCompletedBroadcastReceiver(AccessibilityManagerService.java:278)
04-06 18:37:26.082: A/SystemServer(332):	at com.android.server.accessibility.AccessibilityManagerService.<init>(AccessibilityManagerService.java:172)
04-06 18:37:26.082: A/SystemServer(332):	at com.android.server.ServerThread.run(SystemServer.java:279)
04-06 18:37:26.082: A/SystemServer(332): BOOT FAILURE making display ready
04-06 18:37:26.082: A/SystemServer(332): java.lang.NullPointerException
04-06 18:37:26.082: A/SystemServer(332):	at com.android.server.ServerThread.run(SystemServer.java:287)
04-06 18:37:26.082: A/SystemServer(332): BOOT FAILURE performing boot dexopt
04-06 18:37:26.082: A/SystemServer(332): java.lang.NullPointerException
04-06 18:37:26.082: A/SystemServer(332):	at com.android.server.ServerThread.run(SystemServer.java:293)
04-06 18:37:26.082: W/dalvikvm(332): threadid=11: thread exiting with uncaught exception (group=0x2b542210)
04-06 18:37:26.082: I/Process(332): Sending signal. PID: 332 SIG: 9
04-06 18:37:26.082: E/AndroidRuntime(332): Error reporting WTF
04-06 18:37:26.082: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.internal.os.RuntimeInit.wtf(RuntimeInit.java:384)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log$1.onTerribleFailure(Log.java:103)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log.wtf(Log.java:278)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.reportWtf(SystemServer.java:78)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.run(SystemServer.java:282)
04-06 18:37:26.082: W/SystemServer(332): ***********************************************
04-06 18:37:26.082: E/AndroidRuntime(332): Error reporting WTF
04-06 18:37:26.082: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.internal.os.RuntimeInit.wtf(RuntimeInit.java:384)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log$1.onTerribleFailure(Log.java:103)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log.wtf(Log.java:278)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.reportWtf(SystemServer.java:78)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.run(SystemServer.java:289)
04-06 18:37:26.082: W/SystemServer(332): ***********************************************
04-06 18:37:26.082: E/AndroidRuntime(332): Error reporting WTF
04-06 18:37:26.082: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.internal.os.RuntimeInit.wtf(RuntimeInit.java:384)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log$1.onTerribleFailure(Log.java:103)
04-06 18:37:26.082: E/AndroidRuntime(332):	at android.util.Log.wtf(Log.java:278)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.reportWtf(SystemServer.java:78)
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.run(SystemServer.java:295)
04-06 18:37:26.082: E/AndroidRuntime(332): *** FATAL EXCEPTION IN SYSTEM PROCESS: android.server.ServerThread
04-06 18:37:26.082: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.server.ServerThread.run(SystemServer.java:299)
04-06 18:37:26.082: E/AndroidRuntime(332): Error reporting crash
04-06 18:37:26.082: E/AndroidRuntime(332): java.lang.NullPointerException
04-06 18:37:26.082: E/AndroidRuntime(332):	at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:80)
04-06 18:37:26.082: E/AndroidRuntime(332):	at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
04-06 18:37:26.082: E/AndroidRuntime(332):	at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
04-06 18:37:26.092: I/ServiceManager(134): service 'power' died
04-06 18:37:26.092: I/ServiceManager(134): service 'entropy' died
04-06 18:37:26.092: I/ServiceManager(134): service 'telephony.registry' died
04-06 18:37:26.092: I/ServiceManager(134): service 'usagestats' died
04-06 18:37:26.092: I/ServiceManager(134): service 'sensorservice' died
04-06 18:37:26.092: I/ServiceManager(134): service 'batteryinfo' died
04-06 18:37:26.092: E/installd(143): eof
04-06 18:37:26.092: E/installd(143): failed to read size
04-06 18:37:26.092: I/installd(143): closing connection
: E/(): Device disconnected

The only thing I noticed after every recompiling was the last line in the logs:

[*] "F:\Eigene Dateien\Downloads\Android Tools\AutoAPKTool2.0.4\_INPUT_APK\Settings"
recompiling "F:\Eigene Dateien\Downloads\Android Tools\AutoAPKTool2.0.4\_INPUT_APK\Settings"...
I: Smaling...
I: Building resources...
I: Building apk file...
Das System kann das angegebene Laufwerk nicht finden.

It means that the system can't find the specific drive. Why and does it matter? Do you have any clue why it doesn't work? I only copied ic_settings_lockstyle.png, UxpNxtLockScreen.apk, LockscreenStyle.apk and my modified files. Did I miss anything?