User cannot authenticate after signup when object cache enabled

Ive just upgraded to wordpress 3.5.1 and the new object-cache.php version 2.0.2 that users some new switch to blog cache functionality.

We had this issue with the previous version of object cache, but i managed to solve it by delete the users keys when doing signup and activation of the blogs. This cleared the cached password from memcache, that for some reason is wrong.

I tried reimplement this, but it does not work. Ive put this code in my register page:

wp_cache_key_delete("4e76434eea3c9d9cf9cb10bbf3f4a74b92:users:1");
wp_cache_delete('users');

the hash is my KEY SALT

and again on the activation page i use this

wp_cache_key_delete("4e76434eea3c9d9cf9cb10bbf3f4a74b92:users:".$user_id);
wp_cache_delete('users');

This should clear the cached users and their password, so auth will happens against the password in the mysql database.

I added theese 2 functions to object-cache.php to handle they key deletion

#hack by tonny

function wp_cache_key_delete($key) {
global $wp_object_cache;

return $wp_object_cache->key_delete($key);
}

and this

function key_delete($key) {

$mc =& $this->get_mc($group);

$result = $mc->delete($key);

@ ++$this->stats['delete'];
$this->group_ops[$group][] = "delete $id";

if ( false !== $result )
unset($this->cache[$key]);

return $result;
}

Has any of you had similar issues with users not beging able to login when signing up / registering a blog ?