Do check the update from Parker
Yes you must have unique Datastore names (and VM's for that matter) in vCenter. Well Datastore can be duplicated, but each successive add of the same datastore will append (1) to the name then (2) etc..
So you must have this same datastore mounted elsewhere, that's the only reason you see the (1). VMWare uses the unique name not the human readable form to connect. That name you give it is just for show, it's a label.
