Multiple Sidebars issue

I’m using register_sidebars to create multiple sidebars:

function ec_register_sidebars() {
register_sidebars( 3,
	array(
	'name' => 'Sidebar %d',
	'id' => "sidebar-$i",
	'before_widget' => '<li id="%1$s" class="widget %2$s">',
	'after_widget' => '</li>',
	'before_title' => '',
	'after_title' => ''
	)
);

And this is in the theme:

<?php if ( is_active_sidebar( 'Sidebar 1' ) ) : ?>
<?php dynamic_sidebar( 'Sidebar 1' ); ?>
	<?php else : ?>
	No primary sidebar content
<?php endif; ?>

Three sidebars appear within the WP admin. I am able to place widgets in all three. However nothing ever shows up in the theme when I load “Sidebar 1” but “Sidebar 2” and “Sidebar 3” work fine.
What’s the issue?

Thanks