Index: wp-includes/cache.php
===================================================================
--- wp-includes/cache.php	(revision 12376)
+++ wp-includes/cache.php	(working copy)
@@ -166,6 +166,26 @@
 }
 
 /**
+ * Treat all groups as non-persistent when writing to a memcached backend.
+ *
+ * @since 2.9.0
+ */
+
+function wp_cache_enable() {
+	return true;
+}
+
+/**
+ * Restore the normal write behavior of persistent groups when using a memcached backend.
+ *
+ * @since 2.9.0
+ */
+
+function wp_cache_disable() {
+	return true;
+}
+
+/**
  * WordPress Object Cache
  *
  * The WordPress Object Cache is used to save on trips to the database. The