5.2.1-RC2: Fatal trap 12 when ACPI enabled

Hi,

When I boot 5.2.1-RC2 on a ASUS A7Nv8 Deluxe OEM Board (the "OEM" 
meaning it's a A7N8X standard with the Deluxe's MCP-T  
Southbridge) with ACPI enabled I get a "Fatal trap 12".  It 
disappears when I boot without ACPI.

Below are the last lines appearing on the console.

regards,
Robert



GEOM: Configure ad1s1h, start 11261706240 length 2147483648 end 
13409189887
GEOM: Configure ad1s2c, start 0 length 42944186880 end 
41944186879
MBREXT Slice 5 on ad1s3:
[0] f:00 typ:130 s(CHS):1023/254/63 e(CHS):1023/254/63 s:63 
l:1028097
[1] f:00 typ:5 s(CHS):1023/254/63 e(CHS):1023/254/63 s:1028160 
l:65641590
GEOM: Configure ad1s5, start 32256 length 526385664 end 526417919
MBREXT Slice 6 on ad1s3:
[0] f:00 typ 131 s(CHS):1023/254/63 e(CHS):1024/254/63 s:63 
l:65641527
[1] f:00 typ:0 s(CHS):0/0/0 e(CHS):0/0/0 s:0 l:0
GEOM: Configure ad1s6, start 526450176 length 33608461824 end 
34134911999
umass0: at uhub1 port 1 (addr 2) disconnected
umass0: detached
VESA: set_mode(): 24(18) -> 28(1c)
de0: enabling Full Duplex 100baseTX port
umass0: ICSI IC1100 V2.5b, rev 1.10/2.5b, addr 2
umass0:4:0:-1: Attached to scbus4


Fatal trap 12: page fault while in kernel mode
fault virtual address   = 0x20
fault code 		= supervisor read, page not present
instruction pointer	= 0x8:0xc04479bd
stack pointer		= 0x10:0xddfdbc70
frame pointer		= 0x10:0xddfdbc80
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 28 (swi8: tty:sio clock)
trap number		= 12
pVESA: set_mode(): 28(1c) -> 24(18)
anic: page fault

syncing disks, buffers remaining...
done
Uptime: 8s
(probe0:ata0:0:0:0): error 22
(probe0:ata0:0:0:0): Unretryable Error
(probe0:ata0:0:0:0): error 22
(probe0:ata0:0:0:0): Unretryable Error
sbp_logout_all
Shutting down ACPI
Automatic reboot in 15 seconds - press a key on the console to 
abort
--> Press a key on the console to reboot,
--> or switch off the system now.