Setting up custom networks in Hardy

If you use Hardy in a regular laptop fashion, i.e., having it automatically connect to available networks, wired or wireless, it works great. Just set roaming mode on both of your adapters and network-manager will take care of the rest. My problem was wanting to have it act a little differently. I want the wired connection to have a static IP, and having the wireless connected to another network at the same time by DHCP. Here's what I found out to be the simplest way:
1. edit /etc/network/interfaces to have this in there:
auto eth0
iface eth0 inet static
2. uncheck "roaming mode" from the wired connection in Administration > Network, and set the static IP info.

Editing interfaces is necessary; otherwise the system for some reason doesn't know how to take care of eth0, which will be dropped by network-manager after taking off "roaming mode" and set static. Keeping "roaming mode" with wireless connection gives you the option to easily pick an available wireless network from the network-manager applet.

"Certificate contains the same serial number as another certificate" - Firefox with WRT54GL

http://support.mozilla.com/en-US/kb/Certificate+contains+the+same+serial+number+as+another+certificate
You might be hit by this if you access Linksys WRT54GL settings page via SSL - I was anyways. Apparently WRT54GL is one of the routers mentioned in the Mozilla support page that "improperly regenerate their security certificates instead of keeping the same one for the life of the device". Nice job, Cisco!

UPDATE: As time goes by, I started to notice that this happens quite often with self-signed certs, and sometimes deleting the certs themselves doesn't even fix it. The important thing is to also delete the associated CA under Authorities tab, as detailed here by sky76.