推送通知的Android GCM注册/设备ID每次都会更改

Question

我使用此代码获取gcm注册ID。 （的早些时候）

// Make sure the device has the proper dependencies.
        GCMRegistrar.checkDevice(this);

        // Make sure the manifest was properly set - comment out this line
        // while developing the app, then uncomment it when it's ready.
        GCMRegistrar.checkManifest(this);



//        registerReceiver(mHandleMessageReceiver, new IntentFilter(
//                CommonUtilities.DISPLAY_MESSAGE_ACTION));

        // Get GCM registration id
        final String regId = GCMRegistrar.getRegistrationId(this);

        // Check if regid already presents
        if (regId.equals("")) {
            // Registration is not present, register now with GCM           
            GCMRegistrar.register(this, CommonUtilities.SENDER_ID);


        } else {

            AppSharedPreferences.saveDeviceIDPreference(ctx, regId);

            // Device is already registered on GCM
            if (GCMRegistrar.isRegisteredOnServer(this)) {
                // Skips registration.              



//                Toast.makeText(getApplicationContext(), "Already registered with GCM", Toast.LENGTH_LONG).show();
            } else {
                // Try to register again, but not in the UI thread.
                // It's also necessary to cancel the thread onDestroy(),
                // hence the use of AsyncTask instead of a raw thread.
                final Context context = this;
                mRegisterTask = new AsyncTask<Void, Void, Void>() {

                    @Override
                    protected Void doInBackground(Void... params) {
                        // Register on our server
                        // On server creates a new user
                        ServerUtilities.register(context, regId);
                        return null;
                    }

                    @Override
                    protected void onPostExecute(Void result) {
                        mRegisterTask = null;
                    }

                };
                mRegisterTask.execute(null, null, null);
            }
        }

但是，令人震惊的是，它似乎每次执行都会改变， for the same device and same application 。请告诉我可能的原因。

EDITED

将GCM修改为较新版本

gcm = GoogleCloudMessaging.getInstance(this);
new RegisterBackground().execute();

关注this tutorial。

但是，仍然有相同的行为，即每次安装都会获得新的注册。