If a new ObjectState is created, you can't create a role that uses it to limit any function because it's not displayed, giving the impression the ObjectState does not exist.
This happens because the cache is not being cleaned after the ObjectState creation. If you clean the caches manually, the ObjectState Will be displayed on the policies limitation.
Note: This problem started to happen on eZ Publish 5.1
1) Create a new ObjectState with two values: true/false
2) Edit the admin role and try to add a new Content\edit policy, limited by ObjectState true.
3) The ObjectStates column won't be displayed
4) Clear the caches
5) Now it's possible to choose the ObjectState