I'm getting the following exception on a 0.7.9 node before the node crashes. I don't have this problem with the other nodes running 0.7.8. Does anyone know what the problem is?

ERROR [Thread-47] 2011-10-05 05:07:03,840 AbstractCassandraDaemon.java (line 133) Fatal exception in thread Thread[Thread-47,5,main]
java.util.concurrent.RejectedExecutionException: ThreadPoolExecutor has shut down
    at org.apache.cassandra.concurrent.DebuggableThreadPoolExecutor$1.rejectedExecution(DebuggableThreadPoolExecutor.java:76)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:816)
    at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1337)
    at org.apache.cassandra.net.MessagingService.receive(MessagingService.java:385)
    at org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:114)