Version:           0.2 (using 3.5.9, Kubuntu (hardy) 4:3.5.9-0ubuntu7)
Compiler:          Target: x86_64-linux-gnu
OS:                Linux (x86_64) release 2.6.24-16-generic

I have tried Hardy on two computers which have wireless interfaces which both previously worked fine with earlier versions of Kubuntu.  In both cases, the symptoms are identical:

KNetworkManager sees the Access Point and gives a good indication of signal strength.  It also sees other Access Points in the area.  However, when I enter the WEP key, it times out with a failure message.

If I then try to do the settings the other way round, eg using the Network Settings dialog in the System Settings application, I can enter all the data, (including the WEP key), but wireless is not properly enabled (eg it doesn't provide a route to the internet).  In previous versions of Kubuntu, I've always found that after this initial setup a reboot is needed, to get wireless to work.  In this case all the fields in the Network Settings dialog are blank again after a restart.  If I exit the System Settings application and restart it without a reboot, the settings remain, (but still won't work).  I've tried to disable and re-enable the network before rebooting, but this has no effect.

I can get wireless to work using the information at  http://www.ubuntugeek.com/how-to-troubleshoot-wireless-network-connection-in-ubuntu.html, providing I shut down KNetworkManager first, but can't work out how to make it persistent across reboots.  If I try to do the settings manually with KNetworkManager still running I get major errors logged in kern.log and other log files.