I'm running Ubuntu 10.04 on an LG laptop. I'm connecting to my home wireless network with WEP encryption.

The default Network Manager handles this fairly well. However, I prefer using Wicd, since it starts scanning for networks at boot time, saving me an annoying wait after I log in.

I wanted to share the problems I ran into while switching, and how to avoid them.

The solution that worked is as follows:
1. Install the wicd package (with Synaptic, or whatever is your preferred method).
2. Reboot.
3. Now you should have the Wicd icon at the upper right of the screen, along with the Network Manager icon. Click it to check that it can see your wireless networks.
4. Remove the packages network-manager, network-manager-gnome, network-manager-pptp and network-manager-pptp-gnome.
5. Reboot.

The documentation claims that step 1 should uninstall Network Manager automatically. That doesn't happen for me.
If I try to uninstall Network Manager (step 4) together with step 1, Wicd doesn't detect wireless networks at all.
If I don't do step 4 at all, Wicd detects the networks, but cannot connect, giving a "Bad Password" message.

Cheers, hope this helps.