This is just a shot a shot in the dark, but:
I use nm-applet running in stalonetray under fvwm. If I log into gnome, the applet will see the network and let me log in the wireless network. In fvwm, the applet will just spin and spin, trying to connect until it gives up.
I’m using this under Debian Lenny and was curious if anyone else encountered this problem.