Menu doesn't appear after linking to another page with phonegap

I use phonegap,

When linking to another page with simple href my menu stop working.

In my Java class I override onKeyDown() and return false for menu button

@Override
public boolean onKeyDown(int i,KeyEvent e){
    if (i==KeyEvent.KEYCODE_MENU){
        return false;
    }else{
        return true;
    }

}

When I loadUrl fr开发者_运维知识库om the java class I can open the menu (in about.html)

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_menu, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle item selection
    switch (item.getItemId()) {
    case R.id.exit:
        this.finish();
        return true;
    case R.id.about:
        super.loadUrl("file:///android_asset/www/about.html");
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}