route related panic

-Current as of few hours.
FreeBSD phobos.totalterror.net 5.2-CURRENT FreeBSD 5.2-CURRENT #1: Wed Apr 28 18:40:12 EEST 2004     root_at_phobos.totalterror.net:/usr/obj/usr/src/sys/GENERIC  i386
dmesg at www.totalterror.net/freebsd/

Here are the steps i make to panic my machine:
(the machine panics, also if the first interface to bring up is fxp0, and 
ndis0 the second)

# ifconfig ndis0 ssid my_ssid wepmode on wepkey 0x**************************
# ifconfig ndis0 10.0.0.6 netmask 255.255.255.240 up
# route add default 10.0.0.1
# ping -c 10.0.0.1

PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: icmp_seq=0 ttl=255 time=0.249 ms
--- 10.0.0.1 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.249/0.249/0.249/0.000 ms

# ifconfig fxp0 10.0.0.6 netmask 255.255.255.240
ifconfig: ioctl (SIOCAIFADDR): File exists
kernel: arp: **:**:**:**:**:** is using my IP address 10.0.0.6!
# ifconfig ndis0 down
# route change default 10.0.0.1
panic: _mtx_lock_sleep: recursed on non-recursive mutex rtentry _at_ /usr/src/sys/net/route.c:1057
at line 437 in file /usr/src/sys/kern/kern_mutex.c
cpuid = 0;
Debugger("panic");
Stopped at     Debugger+0x46:  xchgl    %ebx,in_Debugger.0
db> trace
Debugger(c07c28d5) at Debugger+0x46
__panic(c07c1cb0,1b5,c07c1d9e,c07cc1f8,c07cc111) at __panic+0x13d
_mtx_lock_sleep(c499d260,0,c07cc111,421) at _mtx_lock_sleep+0xab
_mtx_lock_flags(c499d260,0,c07cc111,421,c49b62ec) at _mtx_lock_flags+0x90
rt_setgate(c499d200,c4e40960,c49b62ec,0,c499d200) at rt_setgate+0x230
route_output(c1996800,c4734b40,80,c1996800,1f80) at route_output+0x5be
raw_usend(c4734b40,0,c1996800,0,0,c46b3bd0) at raw_usend+0x6c
rts_send(c4734b40,0,c1996800,0,0) at rts_send+0x1b
sosend(c4734b40,0,e7f2ec88,c1996800,0) at sosend+0x3fd
soo_write(c46db264,e7f2ec88,c49b6500,0,c46b3bd0) at soo_write+0x46
dofilewrite(c46b3bd0,c46db264,3,804e5e0,80) at dofilewrite+0xbb
write(c46b3bd0,e7f2ed14,3,0,296) at write+0x3e
syscall(2f,2f,2f,804e63c,80) at syscall+0x217
Xint0x80_syscall() at Xint0x80_syscall+0x1f
--- syscall (4, FreeBSD ELF32, write), eip = 0x280c54cb, esp = 0xbfbfecbc, ebp = 0xbfbfece8 ---
db>