scsi_cd or atapicam crash in current.

I am seeing a peculiar, possibly timing sensitive, crash that looks
like if is probably in either atapicam or scsi_cd. The system is
CURRENT as of yesterday morning.

The crash happens frequently when nautilus starts up. It does not
always crash, but does so fairly frequently and leaves my laptop
locked in X with no access to the console. If nautilus starts, the
system continues without problems until X is terminated and restarted.

I managed to get a panic printout by switching back to vty0 (console)
while the X startup was in progress and I am entering the panic by
hand. Slight chance of a typo, but I have checked it a couple of
times.

For some reason I can't explain, I didn't get a crash dump, but I
probably can get one after a future crash. The easy fix is to remove
the DVD/CD-RW drive. FWIW, the system is an IBM T30 and it happens
with either APM or ACPI. I am attaching the dmesg and the config
file. Hopefully the mailer won't strip them.

Fatal trap 18: integer divide fault while in kernel mode
instruction pointer     = 0x8:oxc0139a8b
stack pointer           = 0x10:0xdd5b6a38
frame pointer           = 0x10:0xdd5b6a80
code segment            = base 0x0, limit 0xffff, type 0x1b
                        = DPL 0, pres 1, def32 1, gran 1
processor eflags        = Interrupt enabled, resume, IOPL = 0
current process         = 737 (nautilus)
kernel: type 18 trap, code 0
Stopped at      cdstart+0xcb:   divl    0x30(%ebx), %eax
db> tr
cdstart(c419d500,c4192000,1,c407cc30,c407cc00) at cdstart+0xcb
xpt_run_dev_allocq(c40b8c00,c407cc08,1,c418d800,c419d500) at 
xpt_run_dev_allocq+0xab
xpt_schedule(c419d500,1,0,ce54ec78,dd5b6c70) at xpt_schedule+0xca
cdstrategy(ce54ec78,0,0,0,d439f000) at cdstrategy+0x88
physio(c4197700,dd5b6c70,10,dd5b6b78,c03f4900) at physio+0x2df
spec_read(dd5b6bd0,dd5b6c20,c02b35e3,dd5b6bd0,1020002) at spec_read+0x19a
spec_vnoperate(dd5b6bd0,1020002,c470c850,0,dd5b6c70) at spec_vnoperate+0x18
vn_read(c489d8c4,dd5b6c70,c478ee00,0,c470c850) at vn_read+0x1a3
dofileread(c470c850,c489d8c4,12,bfbfeb40,800) at dofileread+0xd9
read(c470c850,dd5b6d10,c,c,3) at read+0x6b
syscall(2f,2f,2f,80cb000,0) at syscall+0x2b0
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (3, FreeBSD ELF32, read), eip = 0x28da2b5f, esp = 0xbfbfeadc,ebp = 
0xbfbfeb08 ---
db>
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman_at_es.net			Phone: +1 510 486-8634