server keeps BSOD   

Hi Our server 2000 is starting to go down every couple of hours with BSOD
and

Stop 0x000001e (0xC000005, BEA43280,0x0000001,0x0000002)
KMODE_EXCEPTION_NOT_HANDLED
Address BEA43280 base BEA3c000,datestamp 3eaf0356
tcpip.sys

I have check for virus and Intstaled a new NIC ,updated all drivers and 
installed all updates,tested the memory,and HDD all come up fine,I notice 
there is nothing in the event viewer ,,,I have noticed a lot of virus and 
junk email coming thru our exchange server could this cause the stack to 
shutdown a bit like the ping of death?
Any help would be great,
thanks Martin

date: Fri, 27 Jan 2006 20:37:48 +1100   author:   martin