[myTouch 3G, Magic General] Wysie:
I managed to get some logs before the "reboot". Now I know it's a crash:

D/UpdateService( 520): Processing thread started

D/UpdateService( 520): >>>> Activate a backup alarm in 15 minutes in case of service crash

D/UpdateService( 520): 3 : not configured yet, so skipping update (nbInvalidUpdate = 21)

D/UpdateService( 520): 51 : delta since last forecast update is 27.0 min / update_period is 60.0 min

D/UpdateService( 520): 51 : doesn't need update

D/UpdateService( 2570): 33 : launch view update

D/UpdateService( 2570): 33 : providerName = org.koxx.pure_calendar.Cal4x4AppWidget

D/UpdateService( 520): 51 : next update at 1256667594000, in 32.0 min

D/UpdateService( 520): >>>> Requesting next update at 1256667594000, in 32.0 min <<<<

I/ActivityManager( 72): Stopping service: org.koxx.forecast_weather.v2/.UpdateService

D/dalvikvm( 2570): GC freed 5974 objects / 363472 bytes in 239ms

D/dalvikvm( 2548): GC freed 6568 objects / 307560 bytes in 332ms

D/UpdateService( 2570): 33 : updateAppWidget (push update to remote view)

D/UpdateService( 2570): 48 : delta since last forecast update is 2.0944426E7 min / update_period is 1440.0 min

D/UpdateService( 2570): 48 : need update

D/UpdateService( 2570): 48 : request calendar update

D/UpdateService( 2570): 48 : next update at 1256752018000, in 1439.0 min

D/UpdateService( 2570): 48 : launch view update

D/UpdateService( 2570): 48 : providerName = org.koxx.pure_calendar.Cal4x4AppWidget

D/dalvikvm( 2570): GC freed 4627 objects / 275512 bytes in 177ms

D/dalvikvm( 379): GC freed 3791 objects / 250552 bytes in 222ms

D/FileSystemProvider( 2548): getType uri:content://com.metago.astro.filesystem/sdcard/.org.koxx.pure_messenger query:null authority:com.metago.astro.filesystem shceme:content path:/sdcard/.org.koxx.pure_messenger

D/FileCreator( 2548): creatExtFile path:/sdcard/.org.koxx.pure_messenger

D/MenuDialog( 2548): PrepareToShow allenabled:true

E/dalvikvm-heap( 72): 512000-byte external allocation too large for this process.

E/ ( 72): VM won't let us allocate 512000 bytes

E/JavaBinder( 72): *** Uncaught remote exception! (Exceptions are not yet supported across processes.)

E/JavaBinder( 72): java.lang.OutOfMemoryError: bitmap size exceeds VM budget

E/JavaBinder( 72):	at android.graphics.Bitmap.nativeCreateFromParcel(Native Method)

E/JavaBinder( 72):	at android.graphics.Bitmap.access$000(Bitmap.java:29)

E/JavaBinder( 72):	at android.graphics.Bitmap$1.createFromParcel(Bitmap.java:870)

E/JavaBinder( 72):	at android.graphics.Bitmap$1.createFromParcel(Bitmap.java:876)

E/JavaBinder( 72):	at android.widget.RemoteViews$ReflectionAction.<init>(RemoteViews.java:323)

E/JavaBinder( 72):	at android.widget.RemoteViews.<init>(RemoteViews.java:490)

E/JavaBinder( 72):	at android.widget.RemoteViews$1.createFromParcel(RemoteViews.java:905)

E/JavaBinder( 72):	at android.widget.RemoteViews$1.createFromParcel(RemoteViews.java:908)

E/JavaBinder( 72):	at com.android.internal.appwidget.IAppWidgetService$Stub.onTransact(IAppWidgetService.java:143)

E/JavaBinder( 72):	at android.os.Binder.execTransact(Binder.java:287)

E/JavaBinder( 72):	at dalvik.system.NativeStart.run(Native Method)

I/XT9IME ( 1963): [finishInput]

W/dalvikvm( 72): threadid=87: thread exiting with uncaught exception (group=0x4001da20)

E/AndroidRuntime( 72): Uncaught handler: thread Binder Thread #15 exiting due to uncaught exception

E/AndroidRuntime( 72): *** EXCEPTION IN SYSTEM PROCESS. System will crash.

Followed by many services dying and then the system reboots, uptime remains unchanged. I did some searching and found this: http://xdaforums.com/showthread.php?p=4529939

So the problem in this case might be this: E/AndroidRuntime( 72): Uncaught handler: thread Binder Thread #15 exiting due to uncaught exception