Crash during boot on Asus P5N-MX MB

Hi All,

I'm having trouble booting FreeBSD (-current or 6.1) on a new PC using an Asus 
P5N-MX mother board equipped with a Intel E6750 Core 2 Duo processor.
After adding some printf()'s I've found out that the kernel crashes in 
vm/vm_page.c - vm_page_startup()
around the line :
	bzero((void *)mapped, end - new_end);

This is the output of a verbose boot with VERBOSE_SYSINIT and custom 
printf()'s :
GDB: no debug ports present
KDB: debugger backends: ddb
KDB: current backend: ddb
SMAP type=01 base=0000000000000000 len=000000000009f000
SMAP type=02 base=00000000000f0000 len=0000000000010000
SMAP type=02 base=00000000fec00000 len=0000000001400000
SMAP type=02 base=00000000f0000000 len=0000000002000000
SMAP type=03 base=000000007fef3000 len=000000000000d000
SMAP type=04 base=000000007fef0000 len=0000000000003000
SMAP type=02 base=000000000009f000 len=0000000000001000
SMAP type=01 base=0000000000100000 len=000000007fdf0000
SMAP type=02 base=0000000077000000 len=0000000008000000
SMAP type=01 base=000000007f000000 len=0000000000df0000
Overlapping or non-monotonic memory region, ignoring second region
Copyright (c) 1992-2008 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
	The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 8.0-CURRENT #15: Fri Mar 21 22:06:26 CET 2008
    
root_at_Racebeest.Vitsch.LAN:/home/src-tijdelijk-current/src/sys/i386/compile/GENERIC
WARNING: WITNESS option enabled, expect reduced performance.
subsystem 900000
   mtx_pool_setup_static(0)... 
done.
subsystem 1000000
   vm_mem_init(0)... 
1
2
vm_page_startup() 1
vm_page_startup() before-1st-for phys_avail[0]=0x1000 phys_avail[1]=0x9e000
vm_page_startup() before-1st-for phys_avail[2]=0x100000 phys_avail[3]=0x400000
vm_page_startup() before-1st-for phys_avail[4]=0x1025000
	phys_avail[5]=0x7fdf0000
vm_page_startup() before-1st-for phys_avail[6]=0x7f000000
	phys_avail[7]=0x7fde0000
vm_page_startup() before-2nd-for phys_avail[0]=0x1000 phys_avail[1]=0x9e000
vm_page_startup() before-2nd-for phys_avail[2]=0x100000 phys_avail[3]=0x400000
vm_page_startup() before-2nd-for phys_avail[4]=0x1025000
	phys_avail[5]=0x7fdf0000
vm_page_startup() before-2nd-for phys_avail[6]=0x7f000000
	phys_avail[7]=0x7fde0000
vm_page_startup() 2
vm_page_startup() after-2nd-for phys_avail[0]=0x1000 phys_avail[1]=0x9e000
vm_page_startup() after-2nd-for phys_avail[2]=0x100000 phys_avail[3]=0x400000
vm_page_startup() after-2nd-for phys_avail[4]=0x1025000 
phys_avail[5]=0x7fdf0000
vm_page_startup() after-2nd-for phys_avail[6]=0x7f000000 
phys_avail[7]=0x7fde0000
vm_page_startup() 3
vm_page_startup() 4
vm_page_startup() 5
vm_page_startup() 6
vm_page_startup() 7 going to call bzero() with end=0x7fdf0000
	new_end=0x7fdc0000
v














kkkkkkkkkkkkkkk
---- system reboots here ----

After printing "... goin to call bzero()..." the system halts for a couple of 
seconds. Then it prints the first letter of the printf() I've added directly 
after the call to bzero(), followed by a number of line feeds, followed by a 
row of k's and then the system reboots without entering the debugger.

Has anyone ever seen this, or can someone help debug this problem?


Thanks,                   
-- 
Daan