core dump with bluetooth device

hi there,

i'm running r191076M. when i try to send files from my mobile phone to my
computer via bt the core dumps. here's a backtrace:

Unread portion of the kernel message buffer:
sblastmbufchk: sb_mb 0xc8d54d00 sb_mbtail 0 last 0xc8d54d00
packet tree:
        0xc8d54d00
panic: sblastmbufchk from /usr/src/sys/kern/uipc_sockbuf.c:797
cpuid = 0
KDB: stack backtrace:
db_trace_self_wrapper(c07a4d9e,c56e5b64,c05a9993,c07c5e79,0,...) at
db_trace_self_wrapper+0x26
kdb_backtrace(c07c5e79,0,c07abad5,c56e5b70,0,...) at kdb_backtrace+0x29
panic(c07abad5,c0768a0e,c07aba5a,31d,c8d54d00) at panic+0x114
sblastmbufchk(c8e08b08,c07aba5a,31d,2f1,4,c07aba5a,184) at sblastmbufchk+0xe3
sbcompress(c8e08b08,0,c8d54d00,24e,c8e08b28) at sbcompress+0x256
sbappendrecord_locked(c8e08b08,c8d54d00,c07aba5a,263,c90c91c0,...) at
sbappendrecord_locked+0x10c
sbappendrecord(c8e08b08,c8d54d00,c84e2129,57b,c56e5c3c,...) at
sbappendrecord+0x3d
ng_btsocket_l2cap_input(0,1,c07a650f,54,c7a64e9c,...) at
ng_btsocket_l2cap_input+0xc82
taskqueue_run(c7a64e80,c56e5cc8,c058aa0f,0,0,...) at taskqueue_run+0x108
taskqueue_swi_giant_run(0,0,c079dd37,46d,c79b8cb8,...) at
taskqueue_swi_giant_run+0x13
intr_event_execute_handlers(c792fa90,c79b8c80,c079dd37,4dd,c79b8cf0,...) at
intr_event_execute_handlers+0x10f
ithread_loop(c7a78b60,c56e5d38,c079daad,32d,c792fa90,...) at ithread_loop+0x98
fork_exit(c058b551,c7a78b60,c56e5d38) at fork_exit+0xb8
fork_trampoline() at fork_trampoline+0x8
--- trap 0, eip = 0, esp = 0xc56e5d70, ebp = 0 ---
Uptime: 7h16m51s
Physical memory: 2026 MB
Dumping 203 MB:usb2_do_poll: USB polling is not supported!
Expensive timeout(9) function: 0xc05dccc8(0xc878dd20) 0.183307654 s
 188 172 156 140 124 108 92 76 60 44 28 12

Reading symbols from /boot/modules/nvidia.ko...done.
Loaded symbols for /boot/modules/nvidia.ko
Reading symbols from /boot/kernel/acpi.ko...Reading symbols from
/boot/kernel/acpi.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/acpi.ko
Reading symbols from /boot/kernel/ng_btsocket.ko...Reading symbols from
/boot/kernel/ng_btsocket.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_btsocket.ko
Reading symbols from /boot/kernel/netgraph.ko...Reading symbols from
/boot/kernel/netgraph.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/netgraph.ko
Reading symbols from /boot/kernel/ng_bluetooth.ko...Reading symbols from
/boot/kernel/ng_bluetooth.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_bluetooth.ko
Reading symbols from /boot/kernel/ng_ubt.ko...Reading symbols from
/boot/kernel/ng_ubt.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_ubt.ko
Reading symbols from /boot/kernel/ng_hci.ko...Reading symbols from
/boot/kernel/ng_hci.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_hci.ko
Reading symbols from /boot/kernel/ng_l2cap.ko...Reading symbols from
/boot/kernel/ng_l2cap.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_l2cap.ko
Reading symbols from /boot/kernel/ng_socket.ko...Reading symbols from
/boot/kernel/ng_socket.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/ng_socket.ko
#0  doadump () at pcpu.h:246
246     pcpu.h: No such file or directory.
        in pcpu.h
(kgdb) bt
#0  doadump () at pcpu.h:246
#1  0xc05a96e9 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:420
#2  0xc05a99cf in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:576
#3  0xc0603574 in sblastmbufchk (sb=0x0, file=0xc07aba5a
"/usr/src/sys/kern/uipc_sockbuf.c", line=797) at
/usr/src/sys/kern/uipc_sockbuf.c:427
#4  0xc0604b15 in sbcompress (sb=0xc8e08b08, m=0x0, n=0xc8d54d00) at
/usr/src/sys/kern/uipc_sockbuf.c:797
#5  0xc0604c29 in sbappendrecord_locked (sb=0xc8e08b08, m0=0xc8d54d00) at
/usr/src/sys/kern/uipc_sockbuf.c:601
#6  0xc0604c6e in sbappendrecord (sb=0xc8e08b08, m0=0xc8d54d00) at
/usr/src/sys/kern/uipc_sockbuf.c:612
#7  0xc84d7005 in ng_btsocket_l2cap_input (context=0x0, pending=1) at
/usr/src/sys/modules/netgraph/bluetooth/socket/../../../../netgraph/bluetooth/socket/ng_btsocket_l2cap.c:1458
#8  0xc05df273 in taskqueue_run (queue=0xc7a64e80) at
/usr/src/sys/kern/subr_taskqueue.c:282
#9  0xc05df479 in taskqueue_swi_giant_run (dummy=0x0) at
/usr/src/sys/kern/subr_taskqueue.c:336
#10 0xc058aa0f in intr_event_execute_handlers (p=0xc792fa90, ie=0xc79b8c80) at
/usr/src/sys/kern/kern_intr.c:1134
#11 0xc058b5e9 in ithread_loop (arg=0xc7a78b60) at
/usr/src/sys/kern/kern_intr.c:1147
#12 0xc05888b1 in fork_exit (callout=0xc058b551 <ithread_loop>,
arg=0xc7a78b60, frame=0xc56e5d38) at /usr/src/sys/kern/kern_fork.c:821
#13 0xc0716330 in fork_trampoline () at /usr/src/sys/i386/i386/exception.s:270

this is my bt device:

ubt0: <Cambridge Silicon Radio Bluetooth USB dongle, class 224/1, rev
2.00/15.93, addr 2> on usbus0

cheers.
alex