Eu implementei a compra inApp no meu aplicativo, mas às vezes me dá NPE, abaixo está o rastreamento de pilha. Também posso postar o código se alguém estiver interessad

java.lang.RuntimeException: Unable to start service com.market.BillingService@48400380 with null: java.lang.NullPointerException
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3063)
at android.app.ActivityThread.access$3600(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2096)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.market.BillingService.handleCommand(BillingService.java:369)
at com.market.BillingService.onStart(BillingService.java:359)
at android.app.Service.onStartCommand(Service.java:420)
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3053)
... 10 more
java.lang.NullPointerException
at com.market.BillingService.handleCommand(BillingService.java:369)
at com.market.BillingService.onStart(BillingService.java:359)
at android.app.Service.onStartCommand(Service.java:420)
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3053)
at android.app.ActivityThread.access$3600(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2096)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
at dalvik.system.NativeStart.main(Native Method)

Aqui vai o código relevante

@Override
protected void onStart() {
    super.onStart();
    ResponseHandler.register(mDungeonsPurchaseObserver);
}
@Override
protected void onStop() {
    super.onStop();
    ResponseHandler.unregister(mDungeonsPurchaseObserver);
}

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

E no OnCreate ()

mDungeonsPurchaseObserver = new WMBPurchaseObserver(mHandler);

mBillingService = new BillingService();
mBillingService.setContext(BuyModel.this);
ResponseHandler.register(mDungeonsPurchaseObserver);

onClique em comprar Button

if (!mBillingService.checkBillingSupported())
{
    showDialog(DIALOG_CANNOT_CONNECT_ID);
}
mBillingService.requestPurchase("android.test.purchased", null);