The Azure ACS namespace that was just created yesterday shows up as "Disabled" (Active Directory->Access control namespaces->Status). Not sure why. How do I enable it?.
FYI: I had the same namespace name under a different subscription, but that subscription is now disabled. But before the subscription was disabled, that namespace was removed and created under the new subscription (the namespace names are unique, so you wouldn't be able to create the same namespace name if it wasn't deleted).
BTW, The other ACS namespaces created at the same time are "Active" and are fine.