wpa_supplicant causes panic in ieee80211_newstate

-CURRENT supped as of yesterday. Old-ish Dell PIII-600MHz system. I have put
in a Buffalo PCI-PCCard adaptor with WLI-PCM-L11 wireless card, detected as
if_wi.

Now I'm trying to see if I can get it to join a WPA network. I installed
security/wpa_supplicant from ports, and ran it as

  wpa_supplicant -iwi0 -c/usr/local/etc/wpa_supplicant.conf -d
  # based closely on wpa_suppicant.conf.sample

It generated some screens of debug information, ending with

Starting AP scan (broadcast SSID)
Added BSSID 00:00:00:00:00:00 into blacklist
EAPOL: External notification - portEnabled=0
EAPOL: External notification - portValid=0
Disconnect event - remove keys
wpa_driver_bsd_dsl_key: keyidx=0
wpa_driver_bsd_dsl_key: keyidx=1
wpa_driver_bsd_dsl_key: keyidx=2
wpa_driver_bsd_dsl_key: keyidx=3
wpa_driver_bsd_dsl_key: keyidx=0

At this point, a panic occured on the first virtual console:

panic: ieee80211_newstate: bogus xmit rate 0 setup

cpuid = 0
KDB: enter: panic
[thread pid 22 tid 100014 ]
Stopped at      kdb_enter+0x2b: nop
db> trace
Tracing pid 22 tid 100014 td 0xc1521d80
kdb_enter(c08a88ab) at kdb_enter+0x2b
panic(c08b6a4a,c085bbdf,0,c16ae400,c1770000) at panic+0x127
ieee80211_netstate(c177025c,4,ffffffff,c16ae400,782af) at ieee80211_newstate+0x50e
wi_newstate(c1777025c,4,ffffffff) at wi_newstate+0x1bf
wi_info_intr(c17770000) at wi_info_intr+0x107
wi_intr(c17770000) at wi_intr+0x17e
pccard_intr(c1544680,c1775080,cbffed0c,c064622c,c164f880) at pccard_intr+0x60
cbb_func_intr(c164f880) at cbb_func_intr+0x45
ithread_loop(c1544c00,cbffed38,c1544c00,c064610c,0) at ithread_loop+0x120
fork_exit(c064610c,c1544c00,cbffed38) at fork_exit+0xa0
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xcbffed6c, edp = 0 ---
db> ps
...
   22 c1524c00    0     0      0 0000204 [CPU 0] irq11: cbb0 ifpi0+*

Unfortunately I didn't have a dumpdev enabled. I don't know if the above is
much use by itself.

Regards,

Brian.