-current panic: kse/thread mismatch?

Hi everyone,
    Within the past week or so, I have been experiencing severe stability 
problems (i.e., hard lockups) with FreeBSD-current. I am using a stock 
GENERIC kernel (with the exception of 'device atapicam'). Usually these 
lockups occur while I am using Mozilla, XMMS or other X-based applications, 
and until tonight I have been unable to get a kernel panic or other useful 
information to help in diagnosing the problem. This evening, I logged into 
X-Windows and started to play a music file in XMMS. I switched back to the 
text console and captured (by hand) the following panic about 1m30s later:

panic: kse/thread mismatch
cpuid = 1;
boot() called on cpu#1

syncing disks, buffers remaining... panic: pmap_invalidate_range: interrupts 
disabled
cpuid=1;
boot() called on cpu#1
Uptime: 6m6s

The system locked up without dropping me to the debugger, so I am unable to 
provide any useful traceback information, etc ... sorry. I am, however, 
including a copy of my dmesg output from a kernel built earlier tonight ... 
hopefully this will be enough information to help someone diagnose this 
problem. If I can provide any further assistance, don't hesitate to ask. And 
as always, kudos to all of the FreeBSD developers for your hard work and 
patience.

Regards,
Mike

Copyright (c) 1992-2004 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 5.2-CURRENT #3: Mon Jul 12 15:46:43 EDT 2004
    root_at_ulb.neo.rr.com:/usr/obj/usr/src/sys/ULB
WARNING: WITNESS option enabled, expect reduced performance.
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) MP 2100+ (1733.41-MHz 686-class CPU)
  Origin = "AuthenticAMD"  Id = 0x662  Stepping = 2
  
Features=0x383fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CM
OV,PAT,PSE36,MMX,FXSR,SSE>
  AMD Features=0xc0480000<MP,AMIE,DSP,3DNow!>
real memory  = 1073217536 (1023 MB)
avail memory = 1040695296 (992 MB)
ACPI APIC Table: <PTLTD          APIC  >
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
cpu0 (BSP): APIC ID:  1
cpu1 (AP): APIC ID:  0
MADT: Forcing active-low polarity and level trigger for SCI
ioapic0 <Version 1.1> irqs 0-23 on motherboard
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <PTLTD   RSDT> on motherboard
acpi0: [GIANT-LOCKED]
acpi0: Power Button (fixed)
acpi0: Sleep Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x8008-0x800b on acpi0
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0x8080-0x80ff,0x8000-0x807f,0xcf8-0xcff 
iomem
0xd8000-0xdbfff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <AMD 762 host to AGP bridge> port 0x1010-0x1013 mem 
0xeb200000-0xeb200fff,
0xec000000-0xefffffff at device 0.0 on pci0
pcib1: <ACPI PCI-PCI bridge> at device 1.0 on pci0
pci1: <ACPI PCI bus> on pcib1
pci1: <display, VGA> at device 5.0 (no driver attached)
isab0: <PCI-ISA bridge> at device 7.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <AMD 768 UDMA100 controller> port 
0xf000-0xf00f,0x376,0x170-0x177,0x3f6
,0x1f0-0x1f7 at device 7.1 on pci0
ata0: at 0x1f0 irq 14 on atapci0
ata1: at 0x170 irq 15 on atapci0
pci0: <bridge, PCI-unknown> at device 7.3 (no driver attached)
pcib2: <ACPI PCI-PCI bridge> at device 16.0 on pci0
pci2: <ACPI PCI bus> on pcib2
ohci0: <OHCI (generic) USB controller> mem 0xe9000000-0xe9000fff irq 19 at 
devic
e 0.0 on pci2
ohci0: [GIANT-LOCKED]
usb0: OHCI version 1.0, legacy support
usb0: <OHCI (generic) USB controller> on ohci0
usb0: USB revision 1.0
uhub0: AMD OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 4 ports with 4 removable, self powered
atapci1: <HighPoint HPT370 UDMA100 controller> port 
0x2000-0x20ff,0x2820-0x2823,
0x2828-0x282f,0x2824-0x2827,0x2830-0x2837 irq 16 at device 4.0 on pci2
ata2: at 0x2830 on atapci1
ata3: at 0x2828 on atapci1
ohci1: <NEC uPD 9210 USB controller> mem 0xe9001000-0xe9001fff irq 17 at 
device
5.0 on pci2
ohci1: [GIANT-LOCKED]
usb1: OHCI version 1.0
usb1: <NEC uPD 9210 USB controller> on ohci1
usb1: USB revision 1.0
uhub1: NEC OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 3 ports with 3 removable, self powered
ums0: Logitech USB Mouse, rev 1.10/6.10, addr 2, iclass 3/1
ums0: 3 buttons and Z dir.
ohci2: <NEC uPD 9210 USB controller> mem 0xe9002000-0xe9002fff irq 18 at 
device
5.1 on pci2
ohci2: [GIANT-LOCKED]
usb2: OHCI version 1.0
usb2: <NEC uPD 9210 USB controller> on ohci2
usb2: USB revision 1.0
uhub2: NEC OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub2: 2 ports with 2 removable, self powered
uscanner0: Canon CanoScan, rev 1.00/1.00, addr 2
pci2: <serial bus, USB> at device 5.2 (no driver attached)
pcm0: <Creative EMU10K1> port 0x2800-0x281f irq 18 at device 6.0 on pci2
pcm0: <SigmaTel STAC9708/11 AC97 Codec>
pci2: <display, VGA> at device 7.0 (no driver attached)
xl0: <3Com 3c980C Fast Etherlink XL> port 0x2400-0x247f mem 
0xe9003400-0xe900347
f irq 18 at device 8.0 on pci2
miibus0: <MII bus> on xl0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
xl0: Ethernet address: 00:e0:81:22:5b:f4
xl0: [GIANT-LOCKED]
xl1: <3Com 3c980C Fast Etherlink XL> port 0x2480-0x24ff mem 
0xe9003800-0xe900387
f irq 19 at device 9.0 on pci2
miibus1: <MII bus> on xl1
ukphy1: <Generic IEEE 802.3u media interface> on miibus1
ukphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
xl1: Ethernet address: 00:e0:81:22:5b:f5
xl1: [GIANT-LOCKED]
atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
sio0 port 0x3f8-0x3ff irq 4 on acpi0
sio0: type 16550A
sio1 port 0x2f8-0x2ff irq 3 on acpi0
sio1: type 16550A
ppc0 port 0x778-0x77f,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
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
fdc0: <Enhanced floppy controller (i82077, NE72065 or clone)> port 
0x3f7,0x3f0-0
x3f5 irq 6 drq 2 on acpi0
fdc0: FIFO enabled, 8 bytes threshold
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
orm0: <ISA Option ROMs> at iomem 
0xe0000-0xe3fff,0xcf800-0xcffff,0xcf000-0xcf7ff
on isa0
pmtimer0 on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
Timecounters tick every 10.000 msec
ata0-master: FAILURE - ATAPI_RESET no interrupt
acd0: CDRW <Memorex DVD+R/RW 2.4x8AA> at ata0-master PIO4
ad1: 114473MB <WDC WD1200BB-00CAA1> [232581/16/63] at ata0-slave UDMA100
ata1-slave: FAILURE - ATAPI_RESET no interrupt
ata1-master: FAILURE - ATAPI_RESET no interrupt
afd0: REMOVABLE <IOMEGA ZIP 250 ATAPI> at ata1-master PIO3
acd1: CDRW <CD-RW IDE5232> at ata1-slave PIO4
ad4: 114473MB <WDC WD1200JB-00CRA1> [232581/16/63] at ata2-master UDMA100
ad6: 76319MB <WDC WD800BB-00CAA0> [155061/16/63] at ata3-master UDMA100
cd0 at ata0 bus 0 target 0 lun 0
cd0: <Memorex DVD+R/RW 2.4x8AA 1.51> Removable CD-ROM SCSI-0 device
cd0: 16.000MB/s transfers
cd0: cd present [2191232 x 2048 byte records]
da0 at ata1 bus 0 target 0 lun 0
da0: <IOMEGA ZIP 250 42.S> Removable Direct Access SCSI-0 device
da0: 11.000MB/s transfers
da0: 239MB (489532 512 byte sectors: 64H 32S/T 239C)
cd1 at ata1 bus 0 target 1 lun 0
cd1: <CDWRITER IDE5232 000F> Removable CD-ROM SCSI-0 device
cd1: 16.000MB/s transfers
cd1: \M-_at_\M-f\M^H\M-_at_`\M-,0\M-B\M-_at_v0\M-Bll\M-5\M-\<\M^_at_^\M-_at_F\^B\^H
SMP: AP CPU #1 Launched!
Mounting root from ufs:/dev/ad4s1a