Reservations not decremented when instances are destroyed

Easily reproduceable by running (on a fresh devstack install) the following Tempest test:

jpipes@uberbox:~/repos/tempest$ nosetests -sv --nologcapture tempest.tests.compute.test_servers_negative
Pass really long metadata while creating a server ... SKIP: Until Bug 1004007 is fixed
Create a server with name length exceeding 256 characters ... ok
Create a server with an unknown flavor ... ok
Create a server with an unknown image ... ok
Pass invalid network uuid while creating a server ... ok
Pass a non existant keypair while creating a server ... ok
Delete a server that belongs to another tenant ... ok
Delete a non existent server ... ok
Pass a server ID that exceeds length limit to delete server ... ok
Pass an invalid string parameter to delete server ... ok
An access IPv4 address must match a valid address pattern ... ok
An access IPv6 address must match a valid address pattern ... ok
Use an unencoded file when creating a server with personality ... ok
Reboot a deleted server ... ok
Rebuild a deleted server ... ok
Create a server with name parameter empty ... ok
Update name of a non-existent server ... ok
Update name of server exceed the name length limit ... ok
Update name of a server that belongs to another tenant ... ok
Update name of the server to an empty string ... ok

----------------------------------------------------------------------
Ran 21 tests in 73.527s

OK (SKIP=1)

During the test run (which creates a *single* server, shared in the test case):

mysql> select * from quota_usages;

+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
| created_at | updated_at | deleted_at | deleted | id | project_id | resource | in_use | reserved | until_refresh |
+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
| 2012-06-05 17:08:44 | 2012-06-05 17:09:16 | NULL | 0 | 1 | 280196a9863341f1a80401a6ae412425 | instances | 1 | 1 | NULL |
| 2012-06-05 17:08:44 | 2012-06-05 17:09:16 | NULL | 0 | 2 | 280196a9863341f1a80401a6ae412425 | ram | 512 | 512 | NULL |
| 2012-06-05 17:08:44 | 2012-06-05 17:09:16 | NULL | 0 | 3 | 280196a9863341f1a80401a6ae412425 | cores | 1 | 1 | NULL |
+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
3 rows in set (0.04 sec)

After the tests complete and the shared server instance is destroyed:

mysql> select * from quota_usages;
+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
| created_at | updated_at | deleted_at | deleted | id | project_id | resource | in_use | reserved | until_refresh |
+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
| 2012-06-05 17:08:44 | 2012-06-05 17:09:58 | NULL | 0 | 1 | 280196a9863341f1a80401a6ae412425 | instances | 0 | 1 | NULL |
| 2012-06-05 17:08:44 | 2012-06-05 17:09:58 | NULL | 0 | 2 | 280196a9863341f1a80401a6ae412425 | ram | 0 | 512 | NULL |
| 2012-06-05 17:08:44 | 2012-06-05 17:09:58 | NULL | 0 | 3 | 280196a9863341f1a80401a6ae412425 | cores | 0 | 1 | NULL |
+---------------------+---------------------+------------+---------+----+----------------------------------+-----------+--------+----------+---------------+
3 rows in set (0.00 sec)

As you can see, the cores and instances reservations are not being cleaned up... BUT, the RAM is!