ufs2 crashes

I´ve been getting these crashes on a DVD-RAM filesystem which gets 
unmounted,
newfs´d, remounted and used. No specific pattern though but they are 
quite frequent.

Not sure if these came after or before ATAng.
db> trace
Debugger(c03e1565,0,c03f09e4,dd7309d0,100) at Debugger+0x55
panic(c03f09e4,c45b12b0,2,0,c03f099e) at panic+0x15f
ufs_dirbad(c4545578,0,c03f099e,0,dd730a4c) at ufs_dirbad+0x52
ufs_lookup(dd730b0c,dd730b48,c02901f1,dd730b0c,dd730c38) at ufs_lookup+0x447
ufs_vnoperate(dd730b0c,dd730c38,dd730c4c,1147,c4030be0) at 
ufs_vnoperate+0x18
vfs_cache_lookup(dd730b8c,dd730ba8,c0294ea2,dd730b8c,c4030be0) at 
vfs_cache_lookup+0x301
ufs_vnoperate(dd730b8c,c4030be0,0,c4030be0,c4030be0) at ufs_vnoperate+0x18
lookup(dd730c24,0,c03e5b6d,a6,c4030be0) at lookup+0x302
namei(dd730c24,dd730c44,c0360b39,c04622f4,dd730c44) at namei+0x1ee
stat(c4030be0,dd730d10,c03f6ad5,3eb,2) at stat+0x52
syscall(2f,2f,2f,80d9a4c,810931c) at syscall+0x253
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (188, FreeBSD ELF32, stat), eip = 0x807bd1f, esp = 
0xbfbff42c, ebp = 0xbfbff4a8 ---
db> panic
panic: from debugger
cpuid = 0; lapic.id = 00000000
boot() called on cpu#0
Uptime: 10h44m8s
pfs_vncache_unload(): 1 entries remaining
Shutting down ACPI
panic: absolutely cannot call smp_ipi_shootdown with interrupts already 
disabled
cpuid = 0; lapic.id = 00000000
boot() called on cpu#0
Uptime: 10h44m8s
pfs_vncache_unload(): 1 entries remaining
Shutting down ACPI
Automatic reboot in 15 seconds - press a key on the console to abort
Rebooting...
cpu_reset called on cpu#0

Copyright (c) 1992-2003 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 5.1-CURRENT #0: Tue Sep  2 20:43:31 EEST 2003
    pete_at_rms21.rommon.net:/usr/src/sys/i386/compile/ROMMON-SERVER5
Preloaded elf kernel "/boot/kernel/kernel" at 0xc056e000.
Preloaded elf module "/boot/kernel/acpi.ko" at 0xc056e244.
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel Pentium III (568.59-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x68a  Stepping = 10
  
Features=0x387fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,SSE>
real memory  = 536805376 (511 MB)
avail memory = 515555328 (491 MB)
Programming 24 pins in IOAPIC #0
IOAPIC #0 intpin 2 -> irq 0
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): apic id:  0, version: 0x00040011, at 0xfee00000
 cpu1 (AP):  apic id:  1, version: 0x00040011, at 0xfee00000
 io0 (APIC): apic id:  2, version: 0x00178011, at 0xfec00000
Pentium Pro MTRR support enabled
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <VIA694 AWRDACPI> on motherboard
pcibios: BIOS version 2.10
Using $PIR table, 8 entries at 0xc00fdbc0
acpi0: power button is handled as a fixed feature programming model.
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0
acpi_cpu0: <CPU> on acpi0
acpi_cpu1: <CPU> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 
0x6000-0x607f,0x5000-0x500f,0x4080-0x40ff,0x4000-0x407f,0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
IOAPIC #0 intpin 19 -> irq 2
IOAPIC #0 intpin 16 -> irq 5
IOAPIC #0 intpin 17 -> irq 10
IOAPIC #0 intpin 18 -> irq 11
agp0: <VIA 82C691 (Apollo Pro) host to PCI bridge> mem 
0xd0000000-0xd3ffffff at device 0.0 on pci0
pcib1: <PCI-PCI bridge> at device 1.0 on pci0
pci1: <PCI bus> on pcib1
isab0: <PCI-ISA bridge> at device 7.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <VIA 82C686B UDMA100 controller> port 0xc000-0xc00f at device 
7.1 on pci0
ata0: at 0x1f0 irq 14 on atapci0
ata1: at 0x170 irq 15 on atapci0
uhci0: <VIA 83C572 USB controller> port 0xc400-0xc41f irq 2 at device 
7.2 on pci0
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 0xc800-0xc81f irq 2 at device 
7.3 on pci0
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
viapropm0: SMBus I/O base at 0x5000
viapropm0: <VIA VT82C686A Power Management Unit> port 0x5000-0x500f at 
device 7.4 on pci0
viapropm0: SMBus revision code 0x40
smbus0: <System Management Bus> on viapropm0
smb0: <SMBus generic I/O> on smbus0
pci0: <display, VGA> at device 9.0 (no driver attached)
fxp0: <Intel 82550 Pro/100 Ethernet> port 0xcc00-0xcc3f mem 
0xdc000000-0xdc01ffff,0xdc041000-0xdc041fff irq 10 at device 10.0 on pci0
fxp0: Ethernet address 00:02:b3:8a:fb:ca
miibus0: <MII bus> on fxp0
inphy0: <i82555 10/100 media interface> on miibus0
inphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
fxp1: <Intel 82550 Pro/100 Ethernet> port 0xd000-0xd03f mem 
0xdc020000-0xdc03ffff,0xdc040000-0xdc040fff irq 2 at device 12.0 on pci0
fxp1: Ethernet address 00:02:b3:8a:fd:b9
miibus1: <MII bus> on fxp1
inphy1: <i82555 10/100 media interface> on miibus1
inphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
atapci1: <HighPoint HPT370 UDMA100 controller> port 
0xe400-0xe4ff,0xe000-0xe003,0xdc00-0xdc07,0xd800-0xd803,0xd400-0xd407 
irq 11 at device 14.0 on pci0
ata2: at 0xd400 on atapci1
ata3: at 0xdc00 on atapci1
fdc0: <Enhanced floppy controller (i82077, NE72065 or clone)> port 
0x3f7,0x3f0-0x3f5 irq 6 drq 2 on acpi0
sio0 port 0x3f8-0x3ff irq 4 on acpi0
sio0: type 16550A, console
sio1 port 0x2f8-0x2ff irq 3 on acpi0
sio1: type 16550A
atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
atkbd0: <AT Keyboard> flags 0x1 irq 1 on atkbdc0
kbd0 at atkbd0
pmtimer0 on isa0
orm0: <Option ROMs> at iomem 
0xcc000-0xcf7ff,0xca000-0xcb7ff,0xc8000-0xc97ff,0xc0000-0xc7fff on isa0
ppc0: parallel port not found.
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x100>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
APIC_IO: Testing 8254 interrupt delivery
APIC_IO: routing 8254 via IOAPIC #0 intpin 2

Timecounters tick every 10.000 msec
IPv6 packet filtering initialized, default to accept, unlimited logging
ipfw2 initialized, divert disabled, rule-based forwarding enabled, 
default to accept, logging unlimited
acpi_cpu: throttling enabled, 2 steps (100% to 50.0%), currently 100.0%
GEOM: create disk ad0 dp=0xc409a270
ad0: 9541MB <Maxtor 31024H2> [19386/16/63] at ata0-master UDMA100
GEOM: create disk ad3 dp=0xc4175a70
ad3: 117800MB <IC35L120AVVA07-0> [239340/16/63] at ata1-slave UDMA100
acd0: DVDR <HL-DT-ST DVDRAM GSA-4040B> at ata2-master PIO4
SMP: AP CPU #1 Launched!
Mounting root from ufs:/dev/ad0s1a
cd0 at ata2 bus 0 target 0 lun 0
cd0: <HL-DT-ST DVDRAM GSA-4040B A104> Removable CD-ROM SCSI-0 device
cd0: 16.000MB/s transfers
cd0: cd present [2236704 x 2048 byte records]
WARNING: / was not properly dismounted
Loading configuration files.
Entropy harvesting: interrupts ethernet point_to_point.
swapon: adding /dev/ad0s1b as swap device
Starting file system checks:
/dev/ad0s1a: 2051 files, 84829 used, 14354 free (450 frags, 1738 blocks, 
0.5% fragmentation)
/dev/ad3s1h: DEFER FOR BACKGROUND CHECKING
/dev/ad0s1f: DEFER FOR BACKGROUND CHECKING
/dev/ad0s1e: DEFER FOR BACKGROUND CHECKING
WARNING: /home was not properly dismounted
]WARNING: /usr was not properly dismounted
WARNING: /var was not properly dismounted
Adding /home/swap/swapfile as additional swap


Pete