Shared Preferences KEY_FIRST_RUN is not working in android 1.6?

I am using the following code to check the application is first time running or not

SharedPreferences pref = getPreferences(MODE_PRIVATE);
if (!pref.contains(KEY_FIRST_RUN)) {
    Some operation
}
pref.edit().putBoolean(K开发者_如何学运维EY_FIRST_RUN, false).commit();

It works all the android versions except android 1.6

Please any one help me any error in my program

Give me some suggestion

The following works for me:

private static String KEY_FIRST_RUN = "";
private SharedPreferences sharedPreferences;
private SharedPreferences.Editor editor;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    sharedPreferences = getPreferences(MODE_PRIVATE);

    if (!sharedPreferences.contains("KEY_FIRST_RUN")) {
        KEY_FIRST_RUN = "something";
        Log.d("First", "First run!");
    } else {
        Log.d("Second...", "Second run...!");
    }

    editor = sharedPreferences.edit();
    editor.putString("KEY_FIRST_RUN", KEY_FIRST_RUN);
    editor.commit();
}