0.8 throwing exception "Failed to find leader" and high-level consumer fails to make progress

Seeing this exception a LOT (3-4 times per second, same log topic).

I'm using external code to feed data to about 50 different log topics over a cluster of 3 Kafka 0.8 brokers. There are 3 ZooKeeper instances as well, all of this is running on EC2. My application creates a high-level consumer (1 per topic) to consumer data from each and do further processing.

The problem is this exception is in the high-level consumer, so my code has no way of knowing that it's become stuck.

This exception does not always appear, but as far as I can tell, once this happens, the only cure is to restart my application's process.

I saw this in 0.8 built from source about 1 week ago, and also am seeing it today after pulling the latest 0.8 sources and rebuilding Kafka.

Thoughts?

Failed to find leader for Set([topic6,0]): java.lang.NullPointerException
at org.I0Itec.zkclient.ZkClient$2.call(ZkClient.java:416)
at org.I0Itec.zkclient.ZkClient$2.call(ZkClient.java:413)
at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:675)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:413)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:409)
at kafka.utils.ZkUtils$.getChildrenParentMayNotExist(ZkUtils.scala:438)
at kafka.utils.ZkUtils$.getAllBrokersInCluster(ZkUtils.scala:75)
at kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:63)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:51)