Don't check for valid fragment when switching to another fragment

    }

    /**

     * Start a new fragment containing a preference panel.  If the prefences

     * Start a new fragment containing a preference panel.  If the preferences

     * are being displayed in multi-pane mode, the given fragment class will

     * be instantiated and placed in the appropriate pane.  If running in

     * single-pane mode, a new activity will be launched in which to show the

        if (mSinglePane) {

            startWithFragment(fragmentClass, args, resultTo, resultRequestCode, titleRes, 0);

        } else {

            if (!isValidFragment(fragmentClass)) {

                throw new IllegalArgumentException("Invalid fragment for this activity: "

                        + fragmentClass);

            }

            Fragment f = Fragment.instantiate(this, fragmentClass, args);

            if (resultTo != null) {

                f.setTargetFragment(resultTo, resultRequestCode);