consistent hard lockup with recent kernels

I get a very repeatable hard freeze of the system when I use firefox and
attempt to download a large iso image.  I've been trying to get a livecd
image from a gentoo.org mirror (needed for something else, I'm a FreeBSD
fan, honest!!) ;)

I suppose this is related to the preemption issues, but don't have
anything to show for it except my dmegs.  I can't access the system at
all to see why it is happening.

CPU: AMD Athlon(tm) 64 Processor 3000+ (2000.09-MHz K8-class CPU)
  Origin = "AuthenticAMD"  Id = 0xfc0  Stepping = 0
 
Features=0x78bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2>
  AMD Features=0xe0500800<SYSCALL,NX,MMX+,LM,3DNow+,3DNow>
real memory  = 1073676288 (1023 MB)
avail memory = 1026048000 (978 MB)
ACPI APIC Table: <AMIINT VIA_K8  >
ioapic0 <Version 0.3> irqs 0-23 on motherboard
acpi0: <AMIINT VIA_K8> on motherboard
acpi0: [GIANT-LOCKED]
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x808-0x80b on acpi0
cpu0: <ACPI CPU> port 0x530-0x537 on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <VIA 8385 host to PCI bridge> mem 0xd0000000-0xd7ffffff at device
0.0 on pci0
pcib1: <PCI-PCI bridge> at device 1.0 on pci0
pci1: <PCI bus> on pcib1
pci1: <display, VGA> at device 0.0 (no driver attached)
xl0: <3Com 3c900B-TPO Etherlink XL> port 0xd400-0xd47f mem
0xcfffbf80-0xcfffbfff irq 19 at device 8.0 on pci0
xl0: selecting 10baseT transceiver, half duplex
xl0: Ethernet address: 00:10:5a:1f:dd:eb
xl0: [GIANT-LOCKED]
re0: <RealTek 8169S Single-chip Gigabit Ethernet> port 0xd000-0xd0ff mem
0xcfffbe00-0xcfffbeff irq 16 at device 11.0 on pci0
miibus0: <MII bus> on re0
rgephy0: <RTL8169S/8110S media interface> on miibus0
rgephy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseTX,
1000baseTX-FDX, auto
re0: Ethernet address: 00:0c:76:e9:2c:58
re0: [GIANT-LOCKED]
atapci0: <VIA 6420 SATA150 controller> port
0xd800-0xd8ff,0xdc00-0xdc0f,0xe000-0xe003,0xe400-0xe407,0xe800-0xe803,0xec00-0xec07 irq 20 at device 15.0 on pci0
ata2: at 0xec00 on atapci0
ata3: at 0xe400 on atapci0
atapci1: <VIA 8237 UDMA133 controller> port
0xfc00-0xfc0f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 15.1 on pci0
ata0: at 0x1f0 irq 14 on atapci1
ata1: at 0x170 irq 15 on atapci1
uhci0: <VIA 83C572 USB controller> port 0xc000-0xc01f irq 21 at device
16.0 on pci0
uhci0: [GIANT-LOCKED]
usb0: <VIA 83C572 USB controller> on uhci0
usb0: USB revision 1.0
uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
uhci1: <VIA 83C572 USB controller> port 0xc400-0xc41f irq 21 at device
16.1 on pci0
uhci1: [GIANT-LOCKED]
usb1: <VIA 83C572 USB controller> on uhci1
usb1: USB revision 1.0
uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhid0: American Power Conversion Back-UPS RS 1000 FW:7.g3 .D USB FW:g3,
rev 1.10/1.06, addr 2, iclass 3/0
ums0: Logitech USB-PS/2 Optical Mouse, rev 2.00/11.10, addr 3, iclass
3/1
ums0: 3 buttons and Z dir.
uhci2: <VIA 83C572 USB controller> port 0xc800-0xc81f irq 21 at device
16.2 on pci0
uhci2: [GIANT-LOCKED]
usb2: <VIA 83C572 USB controller> on uhci2
usb2: USB revision 1.0
uhub2: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub2: 2 ports with 2 removable, self powered
uhci3: <VIA 83C572 USB controller> port 0xcc00-0xcc1f irq 21 at device
16.3 on pci0
uhci3: [GIANT-LOCKED]
usb3: <VIA 83C572 USB controller> on uhci3
usb3: USB revision 1.0
uhub3: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub3: 2 ports with 2 removable, self powered
ugen0: Prolific Technology Inc. USB-Serial Controller, rev 1.10/3.00,
addr 2
pci0: <serial bus, USB> at device 16.4 (no driver attached)
isab0: <PCI-ISA bridge> at device 17.0 on pci0
isa0: <ISA bus> on isab0
pcm0: <VIA VT8237> port 0xbc00-0xbcff irq 22 at device 17.5 on pci0
pcm0: [GIANT-LOCKED]
pcm0: <Avance Logic ALC655 AC97 Codec>
acpi_button1: <Sleep Button> on acpi0
sio0: configured irq 4 not in bitmap of probed irqs 0
sio0: port may not be enabled
sio0 port 0x3f8-0x3ff irq 4 on acpi0
sio0: type 16550A
ppc0 port 0x778-0x77b,0x378-0x37f irq 7 drq 3 on acpi0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/9 bytes threshold
ppbus0: <Parallel port bus> on ppc0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
orm0: <ISA Option ROM> at iomem 0xe0000-0xe0fff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on
isa0
Timecounter "TSC" frequency 2000086534 Hz quality 800
Timecounters tick every 0.976 msec
ipfw2 initialized, divert enabled, rule-based forwarding enabled,
default to deny, logging disabled
IPsec: Initialized Security Association Processing.
ad0: 117246MB <Maxtor 6Y120L0> [238216/16/63] at ata0-master UDMA133
ad1: 117246MB <Maxtor 6Y120L0> [238216/16/63] at ata0-slave UDMA133
ata1-slave: FAILURE - ATAPI_RESET no interrupt
acd0: DVDR <PIONEER DVD-RW DVR-104> at ata1-master PIO4
acd1: DVDROM <ATAPI DVD-ROM 16X> at ata1-slave PIO4
ad6: 76319MB <ST380013AS> [155061/16/63] at ata3-master SATA150
ar0: 117246MB <ATA RAID1 array> [14946/255/63] status: READY subdisks:
 disk0 READY on ad0 at ata0-master
 disk1 READY on ad1 at ata0-slave
cd0 at ata1 bus 0 target 0 lun 0
cd0: <PIONEER DVD-RW  DVR-104 1.40> Removable CD-ROM SCSI-0 device
cd0: 16.000MB/s transfers
cd0: cd present [1 x 2048 byte records]
cd1 at ata1 bus 0 target 1 lun 0
cd1: <ATAPI DVD-ROM 16X 582F> Removable CD-ROM SCSI-0 device
cd1: 16.000MB/s transfers
cd1: cd present [1562944 x 2048 byte records]