informix session memory usage problem

Hi, we have recently upgraded our informix from 9.21 to 9.40. After upgrade informix consumes all machine memory. We have to stop and start informix. We notice that informix session starts with 5 Mbyte memory than it gets bigger and bigger. One of the process goes up to 365,260,800 total memory and 13,323,056 used memory. I wonder is there a memory usage problem introduced with informix 9.40? and what is the differance between the "total memory" and used memory on "onstat -g ses" output? session #RSAM total used id user tty pid hostname threads memory memory 110 appa - 1107443 e2 1 365260800 13323056 off Yasar Akman