TFTP the respective *.bin BBHN firmware to the router.
http://hsmm-mesh.org/documentation/68-firmware-installation-instructions.html
http://www.dd-wrt.com/wiki/index.php/TFTP_flash

Ok, so I was taking some time this weekend to go through and upgrade all my nodes to 1.0.0. In the process, I pulled out one router (still old version), connected a cat5 to a LAN port and couldn't connect to the web page. That's when I realized it was in access mode. Connected it via a LAN port to another regular (old version) node. Connects my computer to the second node via cat5 and a LAN port, pointed my browser to 172.27.0.2:8080 and brought up the status page. Clicked on setup, changed it from access point to mesh node and rebooted.  

However, after reboot, connected via cat5 on LAN port and still no connection. In fact, the network connection shows "network cable unplugged" regardless of which LAN port I'm plugged into.  When I plug it in I get a slow blink, 1-sec on, 1-sec off. If I treat it like an access point and connect it to another mesh node via a cable, the LAN lights on both nodes flicker like normal. 

I've power cycled it several times, rebooted, etc.  no luck. Any ideas on how to get back into it?

A little something I wrote over on The Verge: http://vrge.co/14e7zIs

That looks like the right kind of gadget.  In the distant past, I got the impression that many devices that were supposed to perform the wireless client function just didn't work in a lot of situations.  In particular, they might work with some devices but not others, or only worked with the same brand of access point.

I have no experience on that particular device.  That one looks like it's intended to be more universally compatible.

If you just want to get the router back to a known state, the TFTP install is a bigger hammer and will probably get you into some routers that are too screwed up to log in to.

It works better if you're using a linux box, but it should work from Windoze as well. 

I thought multiple nameservers were used the way you described, but I learned today that that is not the case under Linux. If the first nameserver returns "not found", the system does not query the second nameserver; it just stops looking. The only time it queries the second nameserver is if it doesn't get a response from the first nameserver. But http://www.unix.com/ip-networking/133552-howto-linux-multihomed-dns-client.html describes a method of configuring things so that queries for names in one domain are sent to one nameserver while queries for names in other domains are sent to a different nameserver. I'll try configuring things this way in the next few days and see if it resolves the problem.

Currently the /etc/resolv.conf on my Pi contains the following:

domain local.mesh
search local.mesh
nameserver 10.217.95.249

10.217.95.249 is the address of the mesh node it's connected to. It looks to me like the network it connects to last overwrites whatever was put there by the first network. Sometimes the wifi network gets initialized and responds to a DHCP request first and sometimes the Ethernet network is first when the Pi is booting, which explains why I sometimes can resolve names on one network and other times on the other network.

I've also noticed that my routing table gets set differently sometimes, and I think that's also related to which network gets initialized first and which comes second. I think the bottom line is that if you connect a Pi or other Linux machine only to a mesh node, things will work correctly by default. But if you connect to a mesh node plus another network then you will have to do some manual configuration to make everything work smoothly.

"Yeah, yeah, what he said!" as he struggled to understand it all.  :-)

That's actually very helpful to understand as I had thought that the router always had some low-level code below the OS which the 30-30-30 and 30-second resets addressed.

You all are giving me an education here!  Thanks!  David

Glad it worked out. If you ever wanted to change the username for the login screen (not the ssh login screen), this is where you would do that too.