Index: wp-admin/includes/class-wp-upgrader.php
===================================================================
--- wp-admin/includes/class-wp-upgrader.php	(revision 17587)
+++ wp-admin/includes/class-wp-upgrader.php	(working copy)
@@ -402,7 +402,8 @@
 
 		// Force refresh of plugin update information
 		delete_site_transient('update_plugins');
-
+		wp_cache_delete('plugins', 'plugins');
+		wp_update_plugins();
 	}
 
 	function upgrade($plugin) {
@@ -445,6 +446,8 @@
 
 		// Force refresh of plugin update information
 		delete_site_transient('update_plugins');
+		wp_cache_delete('plugins', 'plugins');
+		wp_update_plugins();
 	}
 
 	function bulk_upgrade($plugins) {
@@ -526,6 +529,8 @@
 
 		// Force refresh of plugin update information
 		delete_site_transient('update_plugins');
+		wp_cache_delete('plugins', 'plugins');
+		wp_update_plugins();
 
 		return $results;
 	}
@@ -645,6 +650,8 @@
 
 		// Force refresh of theme update information
 		delete_site_transient('update_themes');
+		$GLOBALS['wp_themes'] = null; // break get_themes()'s cache
+		wp_update_themes();
 
 		if ( empty($result['destination_name']) )
 			return false;
@@ -690,6 +697,8 @@
 
 		// Force refresh of theme update information
 		delete_site_transient('update_themes');
+		$GLOBALS['wp_themes'] = null; // break get_themes()'s cache
+		wp_update_themes();
 
 		return true;
 	}
@@ -777,6 +786,8 @@
 
 		// Force refresh of theme update information
 		delete_site_transient('update_themes');
+		$GLOBALS['wp_themes'] = null; // break get_themes()'s cache
+		wp_update_themes();
 
 		return $results;
 	}