JMeter "leaks" by storing the raw data into the heap

almost 1 year ago i wrote about load generated by JMeter decreasing after long time running, looking at this :http://joychester.blogspot.com/2009/01/jmeter-load-get-decreasing-after-long.html

After looking at the Heapdump of JMeter after on day running, we got the suspect:



I prefered to using the Aggregate listener as always, so it indeed to store every single response data into Heap, it may be one of the reason cause Jmeter slower and slower to generate the load itself.