If cache file is damaged, Zend_XmlRpc_Server_Cache get method fail with error messages, most of them over "$server->loadFunctions".

Here a little patch :

Index: Cache.php
===================================================================
--- Cache.php   (revision 6834)
+++ Cache.php   (working copy)
@@ -115,7 +115,9 @@
             return false;
         }
 
-        $dispatchArray = @unserialize($dispatch);
+        if (false === ($dispatchArray = @unserialize($dispatch))) {
+            return false;
+        }
 
         $server->loadFunctions($dispatchArray);