an(4) timeouts after a while?

I use an Aironet 340 card in my laptop, running 7-current.  It will run 
fine for 30-40 minutes and then suddenly timeout.  Ejecting and 
reinserting fixes this.  It may only happen after a suspend/resume, even 
if the suspend/resume was before the card was first inserted.

Here's what I get on insertion:
an0: <Cisco Systems 340 Series Wireless LAN Adapter> at port 
0x2000-0x203f irq 11 function 0 config 5 on pccard1
an0: record length mismatch -- expected 192, got 200 for Rid ff00
an0: got RSSI <-> dBM map
an0: supported rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
an0: Ethernet address: 00:40:xxxxx
an0: [GIANT-LOCKED]

When net connections start hanging, this is ifconfig:
an0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
         inet6 fe80::xx:xx:xx:xx%an0 prefixlen 64 scopeid 0x4
         inet 10.0.xx.xx netmask 0xffffff00 broadcast 10.0.xx.255
         ether 00:40:xx:xx:xx:xx
         media: IEEE 802.11 Wireless Ethernet autoselect
         status: no carrier
         ssid  1:myssid channel 6
         stationname ""
         authmode OPEN privacy ON deftxkey 1 txpowmax 0 rtsthreshold 0
         roaming DEVICE

And dmesg says:
an0: xmit failed
an0: device timeout

Then I eject the card:
an0: RID access failed
an0: RID access failed
an0: detached
cbb1: Bad Vcc requested
Interrupt storm detected on "irq11: pcm0 cbb0+++"; throttling interrupt 
source
cbb1: Bad Vcc requested

And then reinsert:
an0: <Cisco Systems 340 Series Wireless LAN Adapter> at port 
0x2000-0x203f irq 11 function 0 config 5 on pccard1
an0: record length mismatch -- expected 192, got 200 for Rid ff00
an0: got RSSI <-> dBM map
an0: supported rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
an0: Ethernet address: 00:40:xxxxx
an0: [GIANT-LOCKED]

-- 
Nate