Why NullPointerException happens with usage of standard BillingService?

I use standard BillingService in my application (i.e. copied from the sample application without changes). But sometimes my app crashes with the following data in logcat:

04-16 10:05:43.556: INFO/ActivityManager(96): Start proc tv.kinobaza.app for service tv.kinobaza.app/tv.kinobaza.billing.BillingService: pid=28748 uid=10081 gids={3003}
04-16 10:05:43.646: DEBUG/AndroidRuntime(28748): Shutting down VM
04-16 10:05:43.656: WARN/dalvikvm(28748): threadid=1: thread exiting with uncaught exception (group=0x400259f8)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748): FATAL EXCEPTION: main
04-16 10:05:43.656: ERROR/AndroidRuntime(28748): java.lang.RuntimeException: Unable to start service tv.kinobaza.billing.BillingService@4632f578 with null: java.lang.NullPointerException
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3282)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.app.ActivityThread.access$3600(ActivityThread.java:135)
04-16 10:05:43.656:开发者_JS百科 ERROR/AndroidRuntime(28748):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2211)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.os.Looper.loop(Looper.java:144)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.app.ActivityThread.main(ActivityThread.java:4937)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at java.lang.reflect.Method.invokeNative(Native Method)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at java.lang.reflect.Method.invoke(Method.java:521)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at dalvik.system.NativeStart.main(Native Method)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748): Caused by: java.lang.NullPointerException
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at tv.kinobaza.billing.BillingService.onStart(Unknown Source)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.app.Service.onStartCommand(Service.java:420)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3267)
04-16 10:05:43.656: ERROR/AndroidRuntime(28748):     ... 10 more
04-16 10:05:43.736: DEBUG/SurfaceFlinger(96): Layer::setBuffers(this=0xb947a8), pid=96, w=1, h=1
04-16 10:05:43.736: DEBUG/SurfaceFlinger(96): Layer::setBuffers(this=0xb947a8), pid=96, w=1, h=1
04-16 10:05:43.766: DEBUG/SurfaceFlinger(96): Layer::requestBuffer(this=0xb947a8), index=0, pid=96, w=480, h=418 success
04-16 10:05:43.986: DEBUG/dalvikvm(28721): GC_FOR_MALLOC freed 9604 objects / 1369120 bytes in 102ms

Here is the related code:

/**
 * We don't support binding to this service, only starting the service.
 */
@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onStart(Intent intent, int startId) {
    handleCommand(intent, startId);
}

What is wrong here?

What I've noticed - when device sleeps during the night, once I start use it, it crashes within ~5 minutes.

And, here are more details: BillingService started from the Preferences screen of my application. Here the code from the Preferences class:

@Override
protected void onDestroy() {
mBillingService.unbind();
    super.onDestroy();
}

Upd. Probably, I should start this service/unbind in the Main activity?

Here is my proguard.cfg:

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService
-keep class com.android.vending.billing.**

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

-libraryjars /lib/libGoogleAnalytics.jar
-libraryjars /lib/signpost-commonshttp4-1.2.1.1.jar
-libraryjars /lib/signpost-core-1.2.1.1.jar
-dontwarn org.apache.commons.codec.binary.Base64

---

So you get this NPE after proguard and not beforehand.

You must be obfuscating something that you shouldn't like a class extending Application/Activity/Service

You should not obfuscate these classes:

http://proguard.sourceforge.net/index.html#/manual/examples.html (Goto Example 7)

---

Just pointing out the obvious but if proguard were the problem, then we wouldn't see his billing service name in the stack trace. (we would see an obfuscated name, and not tv.kinobaza.billing.BillingService.onStart).

Try this Why Android service crashes with NullPointerException?