Hmmm, about the wifi, keep calm and carry on . . . .
Sorry about false alarm.
Trying again this morning, and find more normal results. Dmesg logs missing bcm firmware and message about getting it (b43/ucode5.fw) which is as expected when firmware is not present. The pc card wifi 'just works' as it should do both wrt the slot and the ath5k (ar2413 chip) since no firmware is required in recent kernels. The Linksys usb authenticates but doesn't get a dhcp lease, which seems to happen in more than one distro - reason unknown at this point. Maybe something to do with wicd and rt73? Don't think I've seen this with NetworkManager.
Think last night's problems probably a result of rebooting straight from using another live CD, the hardware must have been left in an indeterminate state.
Actually when I say the ar2413 card just works, it does all the right things in terms of authentication and getting an ip address but the web behaves very oddly when using it. Slow loading websites, endless wheel spinning, ie pages that claim to be loading but never arrive, etc. Haven't worked out what this is, the driver or what? But not a Salix issue afaict.
Yes, use iwconfig to determine what the system is calling a particular interface since results can vary and it's often necesary to tell wicd what the wifi is called. Often wlanx for example, but sometimes find a distro which calls the same setup ethx.
Just going back to the missing firmware for bcm4318, don't know why it's not present in Salix, but I believe there is free firmware for this chipset as seen in aptosid for example. Something of an oddity, since it's the only firmware aptosid does supply ootb I think, whereas Broadcom in general is often problematic, the more so the more 'free' the distribution concerned.