Update: 1/11/2013 7:18 PM UTC. We have identified this issue is related to account owner permissions and only affects 234 accounts. These accounts were created between 4/11/2011 and 5/30/2011. If you happen to encounter this issue please file a support case with Customer Support. The fix will be deployed on Monday 1/21/2013
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Initial Update: 1/11/13 6:35 PM UTC We are currently investigating issues preventing a small sub-set of our accounts from preforming a DNS rename, please note all other aspects of the service are available and no other issues are identified. . . We'll provide an update when we know more.
Thanks,
-Michael Moore