Index: wp-admin/includes/post.php
===================================================================
--- wp-admin/includes/post.php	(revision 18373)
+++ wp-admin/includes/post.php	(working copy)
@@ -1809,6 +1809,9 @@
 		'help' => array( 'title' => __('Help (Alt + Shift + H)'), 'onclick' => 'fullscreen.help();', 'both' => false )
 	);
 
+	if ( is_multisite() && ( ( ! $mu_media_buttons = get_site_option( 'mu_media_buttons' ) ) || empty( $mu_media_buttons['image'] ) ) )
+		unset( $buttons['image'] );
+
 	$buttons = apply_filters( 'wp_fullscreen_buttons', $buttons );
 
 	foreach ( $buttons as $button => $args ) {