If I modify a DistributedState key's value on one node, that node receives notification via the DSListener's valueHasChanged event. However other nodes in the cluster don't receive this notification. The modification itself is being replicated to other nodes since the correct value is returned if you get the key's value on another node.

The DistributedState implementation was rewritten for 5.0 and the problem doesn't occur in 4.0.5. Coincidentally, the 5.0 AS cluster environment is broken due to deployer problems right now so this may be the cause. However it does appear that replicated works properly.