Index: wp-admin/menu-header.php
===================================================================
--- wp-admin/menu-header.php	(revision 15079)
+++ wp-admin/menu-header.php	(working copy)
@@ -34,7 +34,6 @@
  */
 function _wp_menu_output( $menu, $submenu, $submenu_as_parent = true ) {
 	global $self, $parent_file, $submenu_file, $plugin_page, $pagenow, $typenow;
-
 	$first = true;
 	// 0 = name, 1 = capability, 2 = file, 3 = class, 4 = id, 5 = icon src
 	foreach ( $menu as $key => $item ) {
@@ -44,16 +43,16 @@
 			$class[] = 'wp-first-item';
 			$first = false;
 		}
-		if ( !empty($submenu[$item[2]]) )
+        // Assignment to speedup array index lookups throughout this iteration.
+        $submenu_items = $submenu[$item[2]];
+        
+		if ( !empty($submenu_items) )
 			$class[] = 'wp-has-submenu';
 
 		if ( ( $parent_file && $item[2] == $parent_file ) || ( false === strpos($parent_file, '?') && $self == $item[2] ) ) {
-			if ( !empty($submenu[$item[2]]) )
-				$class[] = 'wp-has-current-submenu wp-menu-open';
-			else
-				$class[] = 'current';
+            $class[] = (!empty($submenu_items)) ? 'wp-has-current-submenu wp-menu-open' : 'current';
 		}
-
+        
 		if ( ! empty($item[4]) )
 			$class[] = $item[4];
 
@@ -62,48 +61,45 @@
 		$id = ! empty($item[5]) ? ' id="' . preg_replace( '|[^a-zA-Z0-9_:.]|', '-', $item[5] ) . '"' : '';
 		$img = '';
 		if ( ! empty($item[6]) ) {
-			if ( 'div' === $item[6] )
-				$img = '<br />';
-			else
-				$img = '<img src="' . $item[6] . '" alt="" />';
+		  $img = ('div' === $item[6]) ? '<br />' : '<img src="' . $item[6] . '" alt="" />';
 		}
 		$toggle = '<div class="wp-menu-toggle"><br /></div>';
 
 		$title = wptexturize($item[0]);
 
 		echo "\n\t<li$class$id>";
-
 		if ( false !== strpos($class, 'wp-menu-separator') ) {
 			echo '<a class="separator" href="?unfoldmenu=1"><br /></a>';
-		} elseif ( $submenu_as_parent && !empty($submenu[$item[2]]) ) {
-			$submenu[$item[2]] = array_values($submenu[$item[2]]);  // Re-index.
-			$menu_hook = get_plugin_page_hook($submenu[$item[2]][0][2], $item[2]);
-			$menu_file = $submenu[$item[2]][0][2];
-			if ( false !== $pos = strpos($menu_file, '?') )
+		} elseif ( $submenu_as_parent && !empty($submenu_items) ) {
+			$submenu_items = array_values($submenu_items);  // Re-index.         
+			$menu_hook = get_plugin_page_hook($submenu_items[0][2], $item[2]);
+			$menu_file = $submenu_items[0][2];
+			if ( false !== ($pos = strpos($menu_file, '?')) )
 				$menu_file = substr($menu_file, 0, $pos);
-			if ( ( ('index.php' != $submenu[$item[2]][0][2]) && file_exists(WP_PLUGIN_DIR . "/$menu_file") ) || !empty($menu_hook)) {
+			if ( !empty($menu_hook) || ('index.php' != $submenu_items[0][2] && file_exists(WP_PLUGIN_DIR . "/$menu_file")) ) {
 				$admin_is_parent = true;
-				echo "<div class='wp-menu-image'><a href='admin.php?page={$submenu[$item[2]][0][2]}'>$img</a></div>$toggle<a href='admin.php?page={$submenu[$item[2]][0][2]}'$class$tabindex>$title</a>";
+				echo "<div class='wp-menu-image'><a href='admin.php?page={$submenu_items[0][2]}'>$img</a></div>$toggle<a href='admin.php?page={$submenu_items[0][2]}'$class$tabindex>$title</a>";
 			} else {
-				echo "\n\t<div class='wp-menu-image'><a href='{$submenu[$item[2]][0][2]}'>$img</a></div>$toggle<a href='{$submenu[$item[2]][0][2]}'$class$tabindex>$title</a>";
+				echo "\n\t<div class='wp-menu-image'><a href='{$submenu_items[0][2]}'>$img</a></div>$toggle<a href='{$submenu_items[0][2]}'$class$tabindex>$title</a>";
 			}
 		} else if ( current_user_can($item[1]) ) {
 			$menu_hook = get_plugin_page_hook($item[2], 'admin.php');
 			$menu_file = $item[2];
-			if ( false !== $pos = strpos($menu_file, '?') )
+			if ( false !== ($pos = strpos($menu_file, '?')) )
 				$menu_file = substr($menu_file, 0, $pos);
-			if ( ('index.php' != $item[2]) && file_exists(WP_PLUGIN_DIR . "/$menu_file") || !empty($menu_hook) ) {
+			if ( !empty($menu_hook) || ('index.php' != $menu_file) && file_exists(WP_PLUGIN_DIR . "/$menu_file") ) {
 				$admin_is_parent = true;
-				echo "\n\t<div class='wp-menu-image'><a href='admin.php?page={$item[2]}'>$img</a></div>$toggle<a href='admin.php?page={$item[2]}'$class$tabindex>{$item[0]}</a>";
+				echo "\n\t<div class='wp-menu-image'><a href='admin.php?page={$menu_file}'>$img</a></div>$toggle<a href='admin.php?page={$menu_file}'$class$tabindex>{$item[0]}</a>";
 			} else {
-				echo "\n\t<div class='wp-menu-image'><a href='{$item[2]}'>$img</a></div>$toggle<a href='{$item[2]}'$class$tabindex>{$item[0]}</a>";
+				echo "\n\t<div class='wp-menu-image'><a href='{$menu_file}'>$img</a></div>$toggle<a href='{$menu_file}'$class$tabindex>{$item[0]}</a>";
 			}
 		}
-
-		if ( !empty($submenu[$item[2]]) ) {
+		if ( !empty($submenu_items) ) {
 			echo "\n\t<div class='wp-submenu'><div class='wp-submenu-head'>{$item[0]}</div><ul>";
 			$first = true;
-			foreach ( $submenu[$item[2]] as $sub_key => $sub_item ) {
+			foreach ( $submenu_items as $sub_key => $sub_item ) {
+			 
+                // If the current user cannot perform this action then skip it.
 				if ( !current_user_can($sub_item[1]) )
 					continue;
 
@@ -115,29 +111,31 @@
 
 				$menu_file = $item[2];
 
-				if ( false !== $pos = strpos($menu_file, '?') )
+				if ( false !== ($pos = strpos($menu_file, '?')) )
 					$menu_file = substr($menu_file, 0, $pos);
 
 				// Handle current for post_type=post|page|foo pages, which won't match $self.
-				if ( !empty($typenow) )
-					$self_type = $self . '?post_type=' . $typenow;
-				else
-					$self_type = 'nothing';
+                $self_type = ( !empty($typenow) ) ? $self . '?post_type=' . $typenow :  'nothing';
 
 				if ( isset($submenu_file) ) {
 					if ( $submenu_file == $sub_item[2] )
 						$class[] = 'current';
 				// If plugin_page is set the parent must either match the current page or not physically exist.
 				// This allows plugin pages with the same hook to exist under different parents.
-				} else if ( (isset($plugin_page) && $plugin_page == $sub_item[2] && (!file_exists($menu_file) || ($item[2] == $self) || ($item[2] == $self_type))) || (!isset($plugin_page) && $self == $sub_item[2]) ) {
-					$class[] = 'current';
-				}
+                } else if ( 
+                    (!isset($plugin_page) && $self == $sub_item[2]) ||                
+                    (isset($plugin_page) 
+                        && $plugin_page == $sub_item[2] 
+                        && (($item[2] == $self_type) || ($item[2] == $self) || file_exists($menu_file) === false)
+                )) {
+                    $class[] = 'current';
+                }
 
 				$class = $class ? ' class="' . join( ' ', $class ) . '"' : '';
 
 				$menu_hook = get_plugin_page_hook($sub_item[2], $item[2]);
 				$sub_file = $sub_item[2];
-				if ( false !== $pos = strpos($sub_file, '?') )
+				if ( false !== ($pos = strpos($sub_file, '?')) )
 					$sub_file = substr($sub_file, 0, $pos);
 
 				$title = wptexturize($sub_item[0]);
@@ -148,6 +146,7 @@
 						$sub_item_url = add_query_arg( array('page' => $sub_item[2]), $item[2] );
 					else
 						$sub_item_url = add_query_arg( array('page' => $sub_item[2]), 'admin.php' );
+                        
 					$sub_item_url = esc_url($sub_item_url);
 					echo "<li$class><a href='$sub_item_url'$class$tabindex>$title</a></li>";
 				} else {