HCL Sametime Forum : Sametime crash often

Hi all,
Sametime V2.5 iSeries (AS/400) crash often. I have looked up all the documents in the forum, I can not find a relevant document that may solve my problem. I am hereby pasting NSD excerpt below. Can anyone advise me how to resolve this issue.

Thank you.

-------------
nsd_20031015_04.09.40.nsd for server: servername

System: IOST01 OS: OS400 Release: V5R2M0

Invocation stack trace

LE_Create_Thread2__FP12crtth_parm_t 1112 QLECRTTH QLESPI [948832]
ThreadWrapper__FPv 1179 OS400MISC STCRSPLTM
ThreadProc__FPv 161 THREAD STOS
run__31STAuthenticationServiceProviderFv 4756 STTHNTCTNS STAUTHMGR
waitMultiple__14WaitableObjectFR6vectorX 886 WTBLOBJECT STOS
waitMultiple__14WaitableObjectFR6vectorX 1200
WaitForMultipleObjects 1787 WINDOWS STCRSPLTM
WaitForSingleObject 1745
__PureVirtualCalled 1 PUREVIRT37 QYPPRT370
abort 5 QC2TERM QC2UTIL1
raise 1125 QC2SIGNL
os400_exception_handler__FP21_INTRPT_Hnd 1181 OS400MISC STCRSPLTM
system 6 QC2SYS QC2SYS
297 QCMDEXC
_C_pep 0 NSD NSD
main 43

Environment Variables

QYPS_AUTH_LEVEL=0
QYPS_DISCOVERY_TIMEOUT=15
QYPS_TRACE=-1
QYPS_SSL=0
QYPS_USER_PASSWORD=1
QYPS_DISC_LCLSUBNET=1
QYPS_DISCOVERY_STARTUP=0
QYPS_FTP_DISCOVERY=1
QYPS_SNMP_DISCOVERY=0
QYPS_EARLIEST_RELEASE=V4R3M0
QYPS_IP_DISCOVERY=
ICU_DATA=/QIBM/ProdData/OS400/icu/data
QYPS_MAXPTF_SIZE=-1
QYPS_MAX_SOCKETS=200
QYPS_SOCKETTIMEOUT=30
QYPS_MAX_CONTIMOUT=180
QYPS_DNS=1
QYPS_RETRY_TIMEOUT=240
QYPS_RETRY_INTERVAL=10
QYPS_AUTORETRY=1
QYPS_COLLECTPTF_IFCHANGED=1
LANG=/QSYS.LIB/QUSRNOTES.LIB/EN_US.LOCALE
NOTES_AS400_SERVER_TYPE=1
QIBM_GETTIMEOFDAY_USE_SFWCLK=N
PATH=/QIBM/PRODDATA/LOTUS/NOTES:/lotus/domino/servername/data:/QIBM/USERDATA/LOTUS/NOTES
NOTES_CONSOLE=QUSRNOTES
NOTES_AS400_SBS_NAME=servername
NOTES_AS400_SERVER_NAME=servername
NOTES_AS400_DATA_DIR=/lotus/domino/servername/data
FaultRecovery=1
Notes_SubprocessConfigFileName=