OnDestroy () will not be called after this.finish ()

Question

OnDestroy () will not be called after this.finish ()

I'm wondering why Motorola Milestone with 2.1-update1 behaves differently than an emulator or, for example, Nexus One. I am trying to exit my application with:

@Override
protected void onPause() {
    if(mayDestroyActivity) this.finish();
    super.onPause();
}

This works well with either the emulator or the Nexus One. onDestroy()called immediately after onPause()and onStop. But not for Milestone. Instead, onDestroy()called when another action is triggered. Its section in the manifest is as follows:

<activity android:name=".MyActivity"  
    android:configChanges="orientation|keyboardHidden"  
 android:label="@string/questionnaire_item"
 android:launchMode="singleInstance"
    android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
 android:windowSoftInputMode="adjustPan">
 <intent-filter>
  <category android:name="android.intent.category.OPENABLE" />
 </intent-filter>
</activity>