IF_BRIDGE problem on RELENG_6

Pardon sending a releng_6 question to current, but the relevant folks all read
here...  I don't know if anything changed in either if_bridge or ath (or maybe
sis?) in RELENG_6 lately (in the last 3 weeks) but I cvsup'd and rebuilt the
day before yesterday to 6.2-PRERELEASE and get no forwarding through if_bridge.
 All ports talk fine individually to the host containing the bridge but nothing
forwards.  STP is NOT enabled.  ifconfig down+up on all 3 individual ports or
bridge port does not help.  Nor does anything obvious in sysctl...

It is annoying because wireless clients can't reach the local server box.

Hardware is a soekris 4801 with a CM-9 and another higher power minipci atheros
board.  I build stable on my laptop and nfs-mount src and obj to the soekris
for install...

This was working till the day before yesterday.  What changed?

pci0: <PCI bus> on pcib0
sis0: <NatSemi DP8381[56] 10/100BaseTX> port 0xe100-0xe1ff mem 0xa0000000-0xa000
0fff irq 10 at device 6.0 on pci0
sis0: Silicon Revision: DP83816A
miibus0: <MII bus> on sis0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
sis0: Ethernet address: 00:00:24:c2:a5:74
sis0: [GIANT-LOCKED]
sis1: <NatSemi DP8381[56] 10/100BaseTX> port 0xe200-0xe2ff mem 0xa0001000-0xa000
1fff irq 10 at device 7.0 on pci0
sis1: Silicon Revision: DP83816A
miibus1: <MII bus> on sis1
ukphy1: <Generic IEEE 802.3u media interface> on miibus1
ukphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
sis1: Ethernet address: 00:00:24:c2:a5:75
sis1: [GIANT-LOCKED]
sis2: <NatSemi DP8381[56] 10/100BaseTX> port 0xe300-0xe3ff mem 0xa0002000-0xa000
2fff irq 10 at device 8.0 on pci0
sis2: Silicon Revision: DP83816A
miibus2: <MII bus> on sis2
ukphy2: <Generic IEEE 802.3u media interface> on miibus2
ukphy2:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
sis2: Ethernet address: 00:00:24:c2:a5:76
sis2: [GIANT-LOCKED]
ath0: <Atheros 5212> mem 0xa0010000-0xa001ffff irq 11 at device 10.0 on pci0
ath0: [GIANT-LOCKED]
ath0: Ethernet address: 00:02:6f:3e:2c:16
ath0: mac 10.4 phy 6.1 radio 6.3
ath1: <Atheros 5212> mem 0xa0020000-0xa002ffff irq 5 at device 14.0 on pci0
ath1: [GIANT-LOCKED]
ath1: Ethernet address: 00:0b:6b:35:8d:2d
ath1: mac 5.9 phy 4.3 radio 3.6

.....
sis1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet6 fe80::200:24ff:fec2:a575%sis1 prefixlen 64 scopeid 0x2
        inet 192.168.170.1 netmask 0xffffff00 broadcast 192.168.170.255
        inet 192.168.170.16 netmask 0xffffffff broadcast 192.168.170.16
        ether 00:00:24:c2:a5:75
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
ath0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 2290
        inet6 fe80::202:6fff:fe3e:2c16%ath0 prefixlen 64 scopeid 0x4
        inet 192.168.170.15 netmask 0xffffff00 broadcast 192.168.170.255
        ether 00:02:6f:3e:2c:16
        media: IEEE 802.11 Wireless Ethernet autoselect mode 11g <hostap>
        status: associated
        ssid AltadenaEg channel 11 bssid 00:02:6f:3e:2c:16
        authmode WPA1+WPA2/802.11i privacy MIXED deftxkey 3 TKIP 2:128-bit
        TKIP 3:128-bit txpowmax 38 bmiss 7 protmode CTS burst dtimperiod 1
        bintval 100
ath1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 2290
        inet6 fe80::20b:6bff:fe35:8d2d%ath1 prefixlen 64 scopeid 0x5
        inet 192.168.170.17 netmask 0xffffff00 broadcast 192.168.170.255
        ether 00:0b:6b:35:8d:2d
        media: IEEE 802.11 Wireless Ethernet autoselect mode 11a <hostap>
        status: associated
        ssid AltadenaEa channel 64 bssid 00:0b:6b:35:8d:2d
        authmode WPA1+WPA2/802.11i privacy MIXED deftxkey 3 TKIP 2:128-bit
        TKIP 3:128-bit txpowmax 35 bmiss 7 burst dtimperiod 1 bintval 100
bridge0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        ether f6:a8:89:a7:04:6f
        priority 32768 hellotime 2 fwddelay 15 maxage 20
        member: sis1 flags=3<LEARNING,DISCOVER>
        member: ath1 flags=3<LEARNING,DISCOVER>
        member: ath0 flags=3<LEARNING,DISCOVER>


I also can't get a 1500 mtu to stick on the ath ports and bridge objects to
attaching them.  Normally it will last long enough to make things work.

-- Pete