The server was unable to allocate from the system nonpaged pool

Hi,
i have Win2003 & Win2000 server which log with event ID:2019 every minutes,
Source: Srv ; The server was unable to allocate from the system nonpaged pool
because the pool was empty. when it happened, the server is freeze, can't VNC
at all, restart will back server to normal but can't last long. on Win2000
server, i can ran poolmon but if ran with any switch like /p /p /b or /c /g
getting Unknown Swtich: so i can't find the tag mapping driver.
from poolmon result;
MmSt Paged with 172741888 Bytes, Diff - 5023
CM Paged with 22991360 Bytes, Diff - 5406
sOBi Paged with 5806432 Bytes, Diff - 90542
LSwi Nonp with 2293760 Bytes, Diff - 1

just wonder which is causing the memory leak? & how to solve it.
should i change IRPstackSize from
http://eventid.net/display.asp?event...ce=Srv&phase=1
article
OR should i set the PoolUsageMaximum to 40 under
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory
Management

please advice. thanks