Here's an example of a user who is experiencing this issue:

<pre>
mysql> select * from reservations where project_id ='cda9642942d24b7cab4bf1d56f61b5e7';
+---------------------+------------+---------------------+--------+--------------------------------------+----------+----------------------------------+-----------------+-------+---------------------+---------+
| created_at          | updated_at | deleted_at          | id     | uuid                                 | usage_id | project_id                       | resource        | delta | expire              | deleted |
+---------------------+------------+---------------------+--------+--------------------------------------+----------+----------------------------------+-----------------+-------+---------------------+---------+
| 2013-07-31 05:36:38 | NULL       | 2013-07-31 05:36:39 | 523281 | b1cbdb12-88a6-4601-8b86-5228f31d1ef2 |     4578 | cda9642942d24b7cab4bf1d56f61b5e7 | security_groups |     1 | 2013-08-01 05:36:38 |  523281 |
| 2013-07-31 05:36:41 | NULL       | 2013-07-31 05:36:42 | 523284 | 5119268c-1ca4-486b-b173-41f18c166880 |     4578 | cda9642942d24b7cab4bf1d56f61b5e7 | security_groups |     1 | 2013-08-01 05:36:41 |  523284 |
| 2013-07-31 05:36:43 | NULL       | 2013-07-31 05:36:44 | 523287 | cfb61f29-f609-4165-b929-773334809869 |     4578 | cda9642942d24b7cab4bf1d56f61b5e7 | security_groups |     1 | 2013-08-01 05:36:43 |  523287 |
| 2013-07-31 05:41:12 | NULL       | NULL                | 523461 | ae97502d-ec53-46e2-aa9b-3ab17ad5bd23 |     4581 | cda9642942d24b7cab4bf1d56f61b5e7 | instances       |     1 | 2013-08-01 05:41:12 |       0 |
| 2013-07-31 05:41:12 | NULL       | NULL                | 523464 | 34845c5c-2281-4177-bb8b-a78f71499d5d |     4584 | cda9642942d24b7cab4bf1d56f61b5e7 | ram             |  8192 | 2013-08-01 05:41:12 |       0 |
| 2013-07-31 05:41:12 | NULL       | NULL                | 523467 | 86da791d-0adb-4c1f-ae60-5368f813552a |     4587 | cda9642942d24b7cab4bf1d56f61b5e7 | cores           |     2 | 2013-08-01 05:41:12 |       0 |
| 2013-07-31 05:48:45 | NULL       | 2013-07-31 05:48:45 | 523812 | f21a32c3-dfdc-4d1e-9ca2-0129200975e3 |     4581 | cda9642942d24b7cab4bf1d56f61b5e7 | instances       |    -1 | 2013-08-01 05:48:44 |  523812 |
| 2013-07-31 05:48:45 | NULL       | 2013-07-31 05:48:45 | 523815 | 277d3c09-8b47-4add-87f3-56230c94be3c |     4584 | cda9642942d24b7cab4bf1d56f61b5e7 | ram             | -8192 | 2013-08-01 05:48:44 |  523815 |
| 2013-07-31 05:48:45 | NULL       | 2013-07-31 05:48:45 | 523818 | efb33b21-de55-4c42-abbb-7ab423a94d45 |     4587 | cda9642942d24b7cab4bf1d56f61b5e7 | cores           |    -2 | 2013-08-01 05:48:44 |  523818 |
+---------------------+------------+---------------------+--------+--------------------------------------+----------+----------------------------------+-----------------+-------+---------------------+---------+
9 rows in set (0.01 sec)

mysql> select * from quota_usages where project_id = 'cda9642942d24b7cab4bf1d56f61b5e7';
+---------------------+---------------------+------------+------+----------------------------------+-----------------+--------+----------+---------------+---------+
| created_at          | updated_at          | deleted_at | id   | project_id                       | resource        | in_use | reserved | until_refresh | deleted |
+---------------------+---------------------+------------+------+----------------------------------+-----------------+--------+----------+---------------+---------+
| 2013-07-31 05:36:38 | 2013-07-31 05:36:44 | NULL       | 4578 | cda9642942d24b7cab4bf1d56f61b5e7 | security_groups |      3 |        0 |             3 |       0 |
| 2013-07-31 05:41:12 | 2013-07-31 05:51:06 | NULL       | 4581 | cda9642942d24b7cab4bf1d56f61b5e7 | instances       |      0 |        1 |             5 |       0 |
| 2013-07-31 05:41:12 | 2013-07-31 05:51:06 | NULL       | 4584 | cda9642942d24b7cab4bf1d56f61b5e7 | ram             |      0 |     8192 |             5 |       0 |
| 2013-07-31 05:41:12 | 2013-07-31 05:51:06 | NULL       | 4587 | cda9642942d24b7cab4bf1d56f61b5e7 | cores           |      0 |        2 |             5 |       0 |
+---------------------+---------------------+------------+------+----------------------------------+-----------------+--------+----------+---------------+---------+
4 rows in set (0.01 sec)

</pre>


I'm not all that familiar with reservations but it looks as if the reservation hasn't been cleaned up properly?

Note we actually usually see the in_use values of the quota_usages table out of sync so this may be a slightly different issue