Logstash 2.1 : Kafka Input

Hi,
I'm experimenting with using kafka as a broker in my elk stack. I have logstash outputting ingested mesages to kafka and then have a second logstash instance consuming that topic from the broker. The version of kafka I'm using is 0.9.0.0...

Messages flow through reasonably well but I see message loss at higher volumes. So, I've enabled jmx access to view activity on the broker and the logstash instances. However, I'm seeing counters incrementing at the logstash kafka input stage even though messages are being passed through to elasticsearch. I see that the consumer version of the input plugin is 0.8.2. Do I need to be running the same version of kafka for the jmx intrface to behave properly?

Regards,
David