panic while browsing with Opera 7

Hi,

Using PR/55509 I installed (native) Opera 7.2B3 on my -current as
of 2 days ago.  I had 3 panics in only a couple of hours while using
Opera 7: 2 times with a GENERIC kernel, 1 time with a custom kernel.
They all look similar:

phys9911# cat /usr/crash/info.9
Good dump found on device /dev/ad0s2b
  Architecture: i386
  Architecture version: 1
  Dump length: 259461120B (247 MB)
  Blocksize: 512
  Dumptime: Wed Aug 13 13:51:35 2003
  Hostname: phys9911.phys.tue.nl
  Versionstring: FreeBSD 5.1-CURRENT #4: Tue Aug 12 09:44:08 CEST 2003
    karelj_at_phys9911.phys.tue.nl:/usr/obj/usr/src/sys/KAYJAY
  Panicstring: witness_warn
  Bounds: 9

(kgdb) bt
#0  doadump () at /usr/src/sys/kern/kern_shutdown.c:240
#1  0xc020c69c in boot (howto=256) at /usr/src/sys/kern/kern_shutdown.c:372
#2  0xc020ca27 in panic () at /usr/src/sys/kern/kern_shutdown.c:550
#3  0xc02322c4 in witness_warn (flags=2, lock=0x0,
    fmt=0xc03becc5 "System call %s returning")
    at /usr/src/sys/kern/subr_witness.c:1076
#4  0xc03656cd in syscall (frame=
      {tf_fs = 158072879, tf_es = -1078001617, tf_ds = -1078001617, tf_edi = 31, tf_esi = 681549252, tf_ebp = -1079140596, tf_isp = -701428364, tf_ebx = 681557420, tf_edx = 681549252, tf_ecx = 681271324, tf_eax = 9, tf_trapno = 22, tf_err = 2, tf_eip = 681402736, tf_cs = 31, tf_eflags = 643, tf_esp = -1079140656, tf_ss = 47}) at /usr/src/sys/i386/i386/trap.c:1076
#5  0xc03554cd in Xint0x80_syscall () at {standard input}:144
---Can't read userspace from dump, or kernel process---

(kgdb)

Something useful in there? Or more info needed?

Karel.