kafka.common.NoBrokersForPartitionException: Partition = null

Hi, all ~

There are 3 zookepers and one broker, Kafka 0.7.2.
I got some temporary problems in zk cluster enviornment, but, any zk
processes didn't go down.

A broker got zk session timeout message, then got zk disconnected and
expired message.
After 10 secs, the broker reconnected to the zk with new zk session id,
then it regitsterd all topics successfully.

But, kafka producers continuously throw
"kafka.common.NoBrokersForPartitionException: Partition = null".
The broker had got back in stable. However, producers didn't stop to throw
the exceptions.

How can I prevent that problem ?

Thanks,