Tried WICD 1.5.9 as a network manager on Debian testing (Squeeze). After apt-get installing and running it, i got the following error:

dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: The name org.wicd.daemon was not provided by any .service files

This is a known bug that should be fixed in future relases. To solve it, i only had to restart dbus and gdm:

/etc/init.d/dbus restart
/etc/init.d/gdm restart

(yes, this will close all your gnome session and applications) then everything worked, at least for me.