Short of replacing the router, is there anything I can do?

root@wrt0:~# ifconfig eth1|grep frame
          RX packets:1961 errors:0 dropped:0 overruns:0 frame:898
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:1965 errors:0 dropped:0 overruns:0 frame:901
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:1969 errors:0 dropped:0 overruns:0 frame:903
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:1973 errors:0 dropped:0 overruns:0 frame:903
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:7808 errors:0 dropped:0 overruns:0 frame:1313
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:8124 errors:0 dropped:0 overruns:0 frame:1680
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:8176 errors:0 dropped:0 overruns:0 frame:1893
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:9778 errors:0 dropped:0 overruns:0 frame:2319
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:9959 errors:0 dropped:0 overruns:0 frame:3144
root@wrt0:~# ifconfig eth1|grep frame
          RX packets:10321 errors:0 dropped:0 overruns:0 frame:3772
root@wrt0:~#

Hm. I am getting same problem with my misconfiguration after an upgrade (and wifi doesn't works) -
You can try the configuration in which wifi works for me (first post of the thread)

http://forum.openwrt.org/viewtopic.php?pid=39012#p39012

That's my lost pings.

root@routy:~$ ifconfig eth1 | grep frame
          RX packets:235 errors:0 dropped:0 overruns:0 frame:707
root@routy:~$ ifconfig eth1 | grep frame
          RX packets:236 errors:0 dropped:0 overruns:0 frame:707
root@routy:~$ ifconfig eth1 | grep frame
          RX packets:240 errors:0 dropped:0 overruns:0 frame:710
root@routy:~$ ifconfig eth1 | grep frame
          RX packets:247 errors:0 dropped:0 overruns:0 frame:719

I couldn't get my wifi to work until I assigned an IP to the wireless interface:

root@wrt0:~# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:0D:0B:2B:9B:CD 
          inet addr:192.168.2.4  Bcast:192.168.2.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10936 errors:0 dropped:0 overruns:0 frame:5014
          TX packets:16230 errors:53 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2471833 (2.3 MiB)  TX bytes:7977647 (7.6 MiB)
          Interrupt:4 Base address:0x1000

I don't understand why the wifi interface needs an IP when it is attached to the bridge:

root@wrt0:~# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.000d0b2b9bcc       no              vlan0
                                                        eth1

I'll take a look at your settings...

eth1      Link encap:Ethernet  HWaddr 00:12:17:B7:E8:76 
          inet addr:192.168.239.11  Bcast:192.168.239.255  Mask:255.255.255.0
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:494 errors:0 dropped:0 overruns:0 frame:1321
          TX packets:1213 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:20964 (20.4 KiB)  TX bytes:206760 (201.9 KiB)
          Interrupt:4 Base address:0x1000

root@routy:~$ brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.001217b7e874       no              vlan0
                                                        eth1
I have same results as you, teegack..

Well, it least it's not just me doing something stupid

Now what? I guess we wait to see if anyone has any ideas. I've got a couple Linksys routers I can try as well.

I checked my other two linksys routers and even with the wireless turned off, they both show frame errors:

eth1      Link encap:Ethernet  HWaddr 00:13:10:A0:6A:36 
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:3727
          TX packets:1522 errors:14 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:102765 (100.3 KiB)
          Interrupt:4 Base address:0x1000

root@wrt2:~# ifconfig eth1
eth1      Link encap:Ethernet  HWaddr 00:14:BF:1B:F4:95 
          UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:21763
          TX packets:2414 errors:1 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:161455 (157.6 KiB)
          Interrupt:4 Base address:0x1000

Anyone have any comments on excessive frame errors?

Bump - getting the exact same problem. 

Buffalo WHR-G54S , dd-wrt.v23 SP2 ...

Anyone gotten lots of frame errors on eth1 (the wifi), and found a workaround / fix ?

wouldn't worry if the modulation bit rate  (wl rate) is maximum (54 Mbps) and the ping times between client and access point are low and constant.
Also Linksys wrt54g(l) units show the same behaviour. Problem, if you may call it that, seems to be that a box is receiving when it is not transmitting. During that receive window it will, apart from packets intended to be received, also receive data from other connections but without proper synchronisity. The crc check will be faulty and frame errors reported. But no guarantee that all those errored frames were ever intended to be received. What counts is whether the wanted frames get all received; the radio keeps statistics of that and when many retransmissions are needed it will reduce the modulation bit rate automatically; that improves signal/noise ratio of the receiver but transmissions also take longer, i.e. chance of interference increases.