11.50.FC8 aio memory pool allocation seems high

after upgrading our client from 11.50.FC5 to 11.50.FC8 (aix) , the engine uses aprx 130 meg more of virtual shared memory. By comparing historical onstats between the two versions the increase is in the aio memory pool (~230 meg) , where on FC5 the usage topped around 90 megs... is there any underlying reason for this ? Our client has a finite shmtotal so we are concerned. This server is one of an ER pair, both are the same version but the aio memory usage on the second server reamained around 90 megs. Engine configured to use KAIO. onstat -g mem | grep aioaio V 700000110fa6040 229683200 29875176 31093 10724 Thx, Mark