Notice: Undefined index

Hi,

Thanx for this module. I have two errors when I activate turbo_path:

Notice: Undefined index: cache_empty in /path/to/drupal/includes/path.inc on line 9

Notice: Undefined index: turbo_path_memcache in /path/to/drupal/sites/all/modules/turbo/contrib/turbo_path/path.memcache.inc on line 17

I use Memcache and I have the module memcache, too.
I've added the $conf[] for the module in my settings.php.

Someone can help me?