Page fault in FreeBSD 5.3 on IBM e325, Dual AMD64 2.2GHz, 4GB RAM, ServeRAID 6M

Hi all,

I got following page fault in FreeBSD 5.3 on IBM e325 with Dual AMD64 
2.2GHz, 4GB RAM and ServeRAID 6M SCSI
controller.

FreeBSD publicc.ub.mng.net 5.3-STABLE FreeBSD 5.3-STABLE #10: Mon Nov 22 
09:19:35 ULAT 2004     root_at_publica.ub.mng.net:/usr/obj/usr/src/sys/AMD  amd64

I compiled kernel with following options:

# SMP support
options         SMP
options         MAXDSIZ=(1024UL*1024*1024)
options         MAXSSIZ=(128UL*1024*1024)
options         DFLDSIZ=(1024UL*1024*1024)
options         PREEMPTION

I'm using apache+mod_ssl-1.3.33+2.8.22, clamav-0.80, exim-4.43+28 and 
mysql-server-4.0.22.
It is web mail server with mysql database backend.

It seems like following page fault occurs when people accesses web intensively.
-----------------------------------------------------------------------------------------------------------------------------
Fatal trap: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address		= 0x18
fault code			= supervisor read, page not present
instruction pointer		= 0x8:0xffffffff8026d693
stack pointer			= 0x10:0xffffffffb36ab850
frame pointer			= 0x10:0x0
code segment			= base 0x0, limit 0xfffff, type 0x1b
				   DPL 0, press 1, long 1, def32 0, gran 1
processor eflags		= interrupt enabled, resume, IOPL = 0
current process		= 44 (swi1: net)
trap number			= 12
panic: page fault
cpuid = 1
boot() called on cpu#1
Uptime: 17m8s
Cannot dump. No dump device defined
-----------------------------------------------------------------------------------------------------------------------------

Is it known problem or should I post it to freebsd-bugs list? How to solve 
this problem?
Is it related to ips driver?
If somebody wants to make closer look into the problem I can give an shell 
account on this server.

thanks in advance,

Ganbold