The v1.0.0.4098 version of the driver in git does not handle nodes which are down and throws a Mongo exception instead of trying other nodes which are up.
This also means it does not check the state of a node in while populating the seedlist. Mongo does not try other nodes when a node is down after the Mongo connection is create.

Steps to reproduce:
1. Setup a replicaset of >1 nodes.
2. Turn off a single node
3. Create Mongo connection with a number of nodes in the connection string
4. Try and insert or query a document in any collection
5. MongoConnectionException is thrown

I'm not sure how this should be handled though, are there guidelines for drivers for handling downed nodes? It would seem bizzare if Mongo itself is resistant to node failures but the drivers aren't.