Index: wp-includes/general-template.php
===================================================================
--- wp-includes/general-template.php	(revision 5363)
+++ wp-includes/general-template.php	(working copy)
@@ -811,7 +811,11 @@
 	global $wp_rich_edit, $pagenow;
 
 	if ( !isset($wp_rich_edit) )
-		$wp_rich_edit = ( 'true' == get_user_option('rich_editing') && !preg_match('!opera[ /][2-8]|konqueror|safari!i', $_SERVER['HTTP_USER_AGENT']) && 'comment.php' != $pagenow && rich_edit_exists() ) ? true : false;
+		$wp_rich_edit = (
+			'true' == get_user_option('rich_editing') &&
+			( ( preg_match('!AppleWebKit/(\d+)!', $_SERVER['HTTP_USER_AGENT'],$match) && $match[1] >= 420 ) || !preg_match('!opera[ /][2-8]|konqueror|safari!i', $_SERVER['HTTP_USER_AGENT']) ) &&
+			'comment.php' != $pagenow && rich_edit_exists()
+		) ? true : false;
 
 	return apply_filters('user_can_richedit', $wp_rich_edit);
 }