[Serusers] nathelper timer error out of memory

Hello all, I have a setup with ser-0.9.6 on a x86-64 Debian Etch system with 8GB RAM. We use SIPP in order to stress test the system. As a first test we try to register about 150,000 users (the Registration requests arrival rate in not our concern at this time). We manage indeed to register 150,000 users and SER can stop/start with this location DB size. My setup concerning memory : config.h : #define PKG_MEM_POOL_SIZE 512*1024*1024 serctl file: STARTOPTIONS='-m 128' Although, at about 15,000-20,000 contacts at location DB, I get the following error, every 30 seconds : ERROR: nathelper::timer: out of memory natelper module config : modparam("nathelper", "rtpproxy_disable", 1) modparam("nathelper", "natping_interval", 30) modparam("nathelper", "ping_nated_only", 1) Searching the mailing list I found the following : http://lists.iptel.org/pipermail/serusers/2004-March/006828.html We actually changed the PKG_MEM_POOL_SIZE to 512*1024*1024 and recompile but we still get this error. thanks for any help, Kostas