This seems to also make it impossible to resize instances that are created this way as well.  When I try to do that through Horizon, it seems to succeed, but the instance size never changes, and I have the following pair of messages in my nova-conductor.log:

2014-08-05 11:31:32.530 25190 ERROR glanceclient.common.http [-] Request returned failure status.
2014-08-05 11:31:32.530 25190 WARNING nova.compute.utils [req-8c7cdf64-495d-43f6-9b90-778fb5f39ddb eaa8a6534774472791a79d3b02ea3a18 4986c16a1f1b4de598a2e77f21685235] [instance: 48361913-f57f-41c7-b83b-84a779a9cda9] Can't access image : Image  could not be found.

Similarly, when trying to resize from the cli:

root@dwd-maas-1:/var/log/nova# nova flavor-list
+--------------------------------------+--------------+-----------+------+-----------+------+-------+-------------+-----------+
| ID                                   | Name         | Memory_MB | Disk | Ephemeral | Swap | VCPUs | RXTX_Factor | Is_Public |
+--------------------------------------+--------------+-----------+------+-----------+------+-------+-------------+-----------+
| 02ed8cd0-84c3-4731-8769-3bf77d752720 | m3.medium    | 4096      | 8    | 0         |      | 1     | 1.0         | True      |
| 17ab5b0c-1839-482b-9998-024163413cb6 | m2.xlarge    | 20480     | 16   | 0         |      | 2     | 1.0         | True      |
| 3df44567-ba32-45e4-b6ca-843b368cb86c | c3.xlarge    | 8192      | 16   | 0         |      | 4     | 1.0         | True      |
| 51fb187f-5ef0-4a2b-bf31-e4fe1a0e971f | m3.large     | 8192      | 32   | 0         |      | 2     | 1.0         | True      |
| 773e7b71-9fb9-4d30-aaa7-3609b14994fa | c3.large     | 4096      | 5    | 0         |      | 2     | 1.0         | True      |
| 7b9b9d29-c724-46af-8d48-b3d9aeb65271 | r3.large     | 16384     | 16   | 0         |      | 2     | 1.0         | True      |
| a200f0e0-ccc7-42d8-8119-84f304e9be61 | c1.medium    | 2048      | 8    | 0         |      | 2     | 1.0         | True      |
| a4cd4480-c19f-4cdc-b2dd-b6cfc32e5bcd | c1.xlarge    | 8192      | 16   | 0         |      | 8     | 1.0         | True      |
| af36a6ff-2215-41ae-9fad-a9871ea788ff | m1.small     | 2048      | 5    | 0         |      | 1     | 1.0         | True      |
| d403462f-786f-40c3-b366-23d49c5827af | m1.xlarge    | 16384     | 16   | 0         |      | 4     | 1.0         | True      |
| d54455f8-e6a7-4b45-9b9d-f149a464e7b4 | m3.2xlarge   | 30720     | 100  | 0         |      | 8     | 1.0         | True      |
| f7844bd1-ad00-4969-9c1e-f0b5f7264090 | m1.tiny      | 512       | 5    | 0         |      | 1     | 1.0         | True      |
+--------------------------------------+--------------+-----------+------+-----------+------+-------+-------------+-----------+
root@dwd-maas-1:/var/log/nova# nova show 48361913-f57f-41c7-b83b-84a779a9cda9 | grep flavor
| flavor                               | m3.large (51fb187f-5ef0-4a2b-bf31-e4fe1a0e971f)          |
root@dwd-maas-1:/var/log/nova# nova resize --poll 48361913-f57f-41c7-b83b-84a779a9cda9 3df44567-ba32-45e4-b6ca-843b368cb86c
Server resizing... 100% complete
Finished
root@dwd-maas-1:/var/log/nova# nova show 48361913-f57f-41c7-b83b-84a779a9cda9 | grep flavor
| flavor                               | m3.large (51fb187f-5ef0-4a2b-bf31-e4fe1a0e971f)          |