Index: core/cache/backends/memcached.py
===================================================================
--- core/cache/backends/memcached.py    (revision 5646)
+++ core/cache/backends/memcached.py    (working copy)
@@ -16,7 +16,7 @@
         self._cache = memcache.Client(server.split(';'))
 
     def get(self, key, default=None):
-        val = self._cache.get(key)
+        val = self._cache.get(key.encode('ascii'))
         if val is None:
             return default
         else: