Okay, I found this to be working:

function arphabet_widgets_init() {
  $args = array(
    'name' => __('Sidebar %d'),
    'id' => "sidebar".$i,
    'before_widget' => '',
    'after_widget' => '',
    'before_title' => '<h4>',
    'after_title' => '</h4>'
  );
  register_sidebars(3, $args);
}
add_action( 'widgets_init', 'arphabet_widgets_init' );

The main difference is how you apply the ID 'id' => "sidebar".$i,. I tried different ways but found this way to be the best.

I also removed the last comma, after the closing </h4>. Only because there are no further key/value pairs in the array.

Finally I slapped on the __() function on “name” since it is some kind of alias function of translate(). I guess it can’t hurt to have it there although I don’t know what good it does.

So, that’s it. I hope this thread can be of help to someone else.

I tried the double quotes but I’m not sure it helped 🙁

When I wrap the sidebar name in the sprintf() function I still get the correct number of sidebars but they all end with 0 (zero). And the original problem persists: the sidebar content disappears on page (wp-admin/widgets.php) reload.

After reading the Function Reference, under Parameters it describes “name” as such:

name - Sidebar name. (Note: If copying from default usage above, remove sprintf( ) wrapper function.)

This made me think that maybe I should’ve left out the sprintf() function when copying the code to my functions.php file.. or maybe my English isn’t good enough 🙁

Just a side note: I’ve seen many examples of how to add multiple sidebars using the singular register_sidebar() function multiple times. However, since there is a register_sidebars() function to use for multiple registrations, that function should be used. Otherwise I just don’t see the point of having this function.