Index: wp-includes/general-template.php
===================================================================
--- wp-includes/general-template.php	(revision 18656)
+++ wp-includes/general-template.php	(working copy)
@@ -1736,9 +1736,9 @@
 
 	if ( !isset( $wp_rich_edit) ) {
 		if ( get_user_option( 'rich_editing' ) == 'true' &&
-			!$is_iphone && // this includes all Safari mobile browsers
 			( ( preg_match( '!AppleWebKit/(\d+)!', $_SERVER['HTTP_USER_AGENT'], $match ) && intval($match[1]) >= 420 ) ||
-				!preg_match( '!opera[ /][2-8]|konqueror|safari!i', $_SERVER['HTTP_USER_AGENT'] ) )
+				!preg_match( '!opera[ /][2-8]|konqueror|safari!i', $_SERVER['HTTP_USER_AGENT'] ) ) &&
+			!( $is_iphone && intval( $match[1] ) < 534 )
 		) {
 			$wp_rich_edit = true;
 		} else {