If I longpress the menu button, I can close all the application. After that I'm not able to get the push notification for my application

Question

I have done push notification using GCM, and it's working perfectly when my application open or when I close my application using the android physical back button, But I cannot be able to get the GCM when I longpress my menu button in mobile, then I can close my application.

This is my manifest

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.vrm.cooling">
<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<permission
    android:name="com.vrm.cooling.permission.C2D_MESSAGE"
    android:protectionLevel="signature" />
<uses-permission android:name="com.vrm.cooling.permission.C2D_MESSAGE" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission
    android:name="android.permission.WRITE_EXTERNAL_STORAGE"
    />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission
    android:name="android.permission.READ_EXTERNAL_STORAGE"
    />

<application
    android:name=".MyActivity"
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/APP_NAME"
    android:theme="@style/App_Theme"
    >
    <activity
        android:name=".MainActivity"
        android:label="@string/APP_NAME"
        android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".LoginActivity"
        android:label="@string/TITLE_ACTIVITY_LOGIN"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="stateHidden|adjustResize"
        >
    </activity>
    <activity
        android:name=".Registration"
        android:label="@string/TITLE_ACTIVITY_REGISTRATION"
        android:screenOrientation="portrait">
    </activity>
    <activity
        android:name=".HomeActivity"
        android:label="@string/TITLE_ACTIVITY_HOME_PAGE"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="adjustPan"
        />


    <activity
        android:name=".PriceSummary"
        android:label="@string/SUM_TITLE"
        android:screenOrientation="portrait">
    </activity>


    <receiver
        android:name="gcm.GcmBroadcastReceiver"

        android:permission="com.google.android.c2dm.permission.SEND" >
        <intent-filter>

            <!-- Receives the actual messages. -->
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <!-- Receives the registration id. -->
            <action android:name="com.google.android.c2dm.intent.REGISTRATION" />

            <category android:name="com.vrm.cooling" />
        </intent-filter>
    </receiver>



    <service android:name="gcm.GcmIntentService" />

    <activity
        android:name=".UpdateProfile"
        android:label="@string/TITLE_ACTIVITY_UPDATE_PROFILE"
        android:screenOrientation="portrait">
    </activity>
    <activity
        android:name=".FGotPassword"
        android:label="@string/TITLE_ACTIVITY_FGOT_PASSWORD"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="adjustResize">
    </activity>


    <activity
        android:name=".SendMailSuccess"
        android:label="@string/MAILBOX_TITLE"
        android:screenOrientation="portrait">
    </activity>
    <activity
        android:name=".ReadMailDetails"
        android:label="@string/MAILBOX_TITLE"
        android:screenOrientation="portrait">
    </activity>

    <activity
        android:name=".ViewImage"
        android:label="@string/TITLE_ACTIVITY_VIEW_IMAGE"
        android:screenOrientation="portrait">
    </activity>

    <activity
        android:name=".ReplyMail"
        android:label="@string/MAILBOX_REPLY"
        android:screenOrientation="portrait">
    </activity>

    <activity
        android:name=".AuditComplianceSummary"
        android:label="@string/PERFORMANCE_TITLE"
        android:screenOrientation="portrait">
    </activity>

    <activity
        android:name=".NewsflashDetails"
        android:label="@string/NEWSFLASH_TITLE"
        android:screenOrientation="portrait">
    </activity>



    <activity
        android:name=".QRScanner"
        android:screenOrientation="portrait">
    </activity>



    <activity
        android:name=".SurveyView"
        android:screenOrientation="portrait">
    </activity>

</application>

Can any one suggest what I missed here to work for my above specified condition ?

Thanks in advance.