Every now and then I feel the need to put up a post purely because it took me ages to find a solution to something online, and I reckon that it might save the next person a bit of time. Apologies to the regular reader for the purely functional nature of this post 
The Background
Linux (or specifically Ubuntu) uses a neat program called Network Manager to manage all the network connections. It’s taken a while for it to get there, but I personally think it’s pretty good. It remembers the details of my home wifi network perfectly, and seems to have a better time connecting than the ‘IBM Access Connections’ program that came preinstalled on the Windows half of my work laptop. However, in my case it took it’s trick of remembering stuff too far.
The Problem
I setup my new Linksys router with WPA2 encryption, which works fine under Linux. Sadly, Windows XP doesn’t come installed with this by default (at least, teh wifes laptop didn’t have it as an option). Rather than faffing about with Windows Updates, I thought it would be easier to change it to standard WPA encryption - took about 30 seconds in the Linksys control panel. However, NetworkManager insisted on continuing to try and connect with WPA2, which doesn’t work. In order to connect to the network, I needed to use the “Manual Configuration” option, which wasn’t ideal.
The Solution
One solution would have been to rename the ESSID on my wifi, but I didn’t want to do that, really. There is, however, a better way. NetworkManager stores all it’s data in “gconf” the registry-like component of gnome. Fire up gconf-editor, and navigate to /system/networking/wireless/networks/. All your saved wireless network details are in there. You can then either delete the entry, or, as I did, edit the wpa_psk_wpa_version from 4 to 2 (if you did the same thing as me in the first place). Problem solved.
mrBen
