nova metadata services returning inconsistent/wrong results

Issue

• The metadata service is occasionally returning the wrong information to an instance.

[root@example]$ curl http://169.254.169.254/latest/meta-data/instance-id
i-000001a2
[root@example]$ curl http://169.254.169.254/latest/meta-data/instance-id
i-00000035

$ nova show example
+--------------------------------------+----------------------------------------------------------+
| Property                             | Value                                                    |
+--------------------------------------+----------------------------------------------------------+
| OS-DCF:diskConfig                    | MANUAL                                                   |
| OS-EXT-AZ:availability_zone          | nova                                                     |
| OS-EXT-SRV-ATTR:host                 | example.local                                            |
| OS-EXT-SRV-ATTR:hypervisor_hostname  | example.local                                            |
| OS-EXT-SRV-ATTR:instance_name        | instance-00000035                                        |
| OS-EXT-STS:power_state               | 1                                                        |
| OS-EXT-STS:task_state                | -                                                        |
| OS-EXT-STS:vm_state                  | active                                                   |
| OS-SRV-USG:launched_at               | 2014-06-03T03:12:38.000000                               |
| OS-SRV-USG:terminated_at             | -                                                        |
| accessIPv4                           |                                                          |
| accessIPv6                           |                                                          |
| config_drive                         |                                                          |
| created                              | 2014-06-03T03:12:29Z                                     |
| flavor                               | m1.medium (3)                                            |
| hostId                               | 102a3f73c32c60368cfbbf6d785600a9048c88c3e0e78e1dad4eb4d6 |
| id                                   | 917166b5-61f6-42aa-b001-cdb77777a3bd                     |
| image                                | RHEL6_x86 (8900cc5f-3849-4a3c-a362-39216c99a567)         |
| key_name                             | matt01                                                   |
| metadata                             | {}                                                       |
| example-net02 network               | 192.168.98.2, 2.2.2.2                                     |
| name                                 | example                                                  |
| os-extended-volumes:volumes_attached | []                                                       |
| progress                             | 0                                                        |
| security_groups                      | default                                                  |
| status                               | ACTIVE                                                   |
| tenant_id                            | 77999e9f222142409c681203bef90f38                         |
| updated                              | 2014-06-18T15:55:33Z                                     |
| user_id                              | 66841b17147348f2a8d1a3a7036ceb71                         |
+--------------------------------------+----------------------------------------------------------+