Also ManualReconnectionToSingleServerTest looks dodgy to me- it's throwing various exceptions but passes.
I am still seeing these in the logs!!
I made a pass on the last successful hudson run and fixed some tests.
The only tests which does not close their sessions are CloseConnectionOnGCTest and SessionCloseOnGCTest (which is normal) and MultiThreadCompactorTest (which is not).
I have not yet figured out why the warning is logged for MultiThreadCompactorTest while the test close its sessions in a finally block...