Kernel Panic on FreeBSD 6.1 with Dell PE1850 / 1750

[Mike]

Hello,

I got a handful of Dell PE1850 and PE1750 boxes running mail 
scanning that we recently upgraded to FreeBSD 6.1.

It started with a new PE1850 (mx4) that we immediately installed 6.1
on, which started having kernel panics- we initially blamed it
on hardware. But last week, we rebuild a PE1750 (mx6) we've been
running for over a year with FBSD 4.11 without any problems,
and it's crashing now as well.

Are there any known issues with FreeBSD 6.1 on any of the Dell
PE series machines?

Any thoughts would be great,

Mike


Some details:

PE1850
--snip--

FreeBSD mx4 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Mon May 15 18:55:30 PDT 2006
mike at build.office:/usr/obj/usr/src/sys/U_GENERIC_SMP  i386

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address	= 0x5c
fault code		= supervisor read, page not present
instruction pointer	= 0x20:0xc072dbda
stack pointer		= 0x28:0xea9b9a98
frame pointer		= 0x28:0xea9b9b28
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		= 20764 (exim-4.60-1)
trap number		= 12
panic: page fault
cpuid = 0
Uptime: 10d13h1m4s
Dumping 3071 MB (2 chunks)
  chunk 0: 1MB (159 pages) ... ok
  chunk 1: 3071MB (786112 pages) 3055 3039 3823 3007 2991

--snip--


PE1750
--snip--

FreeBSD mx6 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Mon May 15 18:55:30 PDT 2006
mike at build.office:/usr/obj/usr/src/sys/U_GENERIC_SMP  i386

Fatal trap 12: page fault while in kernel mode
cpuid = 2; apic id = 06
fault virtual address	= 0x5c
fault code		= supervisor read, page not present
instruction pointer	= 0x20:0xc072dbda
stack pointer		= 0x28:0xf2791a98
frame pointer		= 0x28:0xf2791b28
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		= 60007 (exim-4.60-1)
trap number		= 12
panic: page fault
cpuid = 2
Uptime: 2d16h44m0s
Dumping 3071 MB (2 chunks)
  chunk 0: 1MB (159 pages) ... ok
  chunk 1: 3071MB (786135 pages) 3055 3039

--snip--