UPDATE:
Since doing a complete wipe and reinstall, the phone worked fine for about a week. However, in the last few days, I've had a few reboots of the same sort, not as frequent, but still as random. Today, I think I managed to capture a log of the exact moment when the crash took place, but I'm not well versed enough in what the log entries mean, so I thought I'd post an extract here, for more clever minds to investigate (apologies for the length):
09-30 15:47:16.700 W/Watchdog(14305) : *** WATCHDOG KILLING SYSTEM PROCESS: com.android.server.am.ActivityManagerService
09-30 15:47:16.760 I/ActivityThread(8782) : Removing dead content provider: settings
09-30 15:47:16.760 I/ActivityThread(8370) : Removing dead content provider: settings
09-30 15:47:16.760 I/ActivityThread(8326) : Removing dead content provider: settings
09-30 15:47:16.770 I/ActivityThread(4576) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(3787) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(2708) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(24986) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(24762) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(20816) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(14400) : Removing dead content provider: settings
09-30 15:47:16.780 I/ActivityThread(14424) : Removing dead content provider: settings
09-30 15:47:16.790 I/ActivityThread(8208) : Removing dead content provider: settings
09-30 15:47:16.790 I/ActivityThread(7593) : Removing dead content provider: settings
09-30 15:47:16.800 I/ActivityThread(7877) : Removing dead content provider: settings
09-30 15:47:16.800 I/ActivityThread(8791) : Removing dead content provider: settings
09-30 15:47:16.800 I/ActivityThread(7992) : Removing dead content provider: settings
09-30 15:47:16.810 I/ActivityThread(7052) : Removing dead content provider: settings
09-30 15:47:16.810 I/ActivityThread(639) : Removing dead content provider: settings
09-30 15:47:16.890 E/AndroidRuntime(8808) : FATAL EXCEPTION: main
09-30 15:47:16.890 E/AndroidRuntime(8808) : java.lang.NullPointerException
09-30 15:47:16.890 E/AndroidRuntime(8808) : at android.app.ActivityThread.attach(ActivityThread.java:3603)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at android.app.ActivityThread.main(ActivityThread.java:3676)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at java.lang.reflect.Method.invokeNative(Native Method)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at java.lang.reflect.Method.invoke(Method.java:507)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at dalvik.system.NativeStart.main(Native Method)
09-30 15:47:16.890 E/AndroidRuntime(8808) : Error reporting crash
09-30 15:47:16.890 E/AndroidRuntime(8808) : java.lang.NullPointerException
09-30 15:47:16.890 E/AndroidRuntime(8808) : at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:76)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:854)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:851)
09-30 15:47:16.890 E/AndroidRuntime(8808) : at dalvik.system.NativeStart.main(Native Method)
09-30 15:47:24.047 I/SystemServer(8831) : Entered the Android system server!
09-30 15:47:24.057 I/SystemServer(8831) : Entropy Service
09-30 15:47:24.107 I/SystemServer(8831) : Power Manager
09-30 15:47:24.117 I/SystemServer(8831) : Activity Manager
09-30 15:47:24.137 I/ActivityManager(8831) : Memory class: 32
09-30 15:47:24.628 I/SystemServer(8831) : Telephony Registry
09-30 15:47:24.628 I/SystemServer(8831) : Package Manager
09-30 15:47:24.648 I/Installer(8831) : connecting...
I included a few lines before and after the crash event, in case they might be important, but I've also got a copy of the whole log, if that would be helpful, I'll post it as an attachment.
Do you guys think this is worth notifying ihlades about? I'm not able to post on his xda forum, but I can send him a PM if it looks fixable.
Cheers,
Erik