I have solved the two wicd-tray icons in openbox, at least for me.
As previously said in this thread, fluxbox doesn`t read from /etc/xdg/ autostart, so just remove the wicd-tray.desktop file from that location. As root cut and paste it somewhere so that you have a backup of the file if you ever should need it. When you have removed it for /etc/xdg/autostart, then logout and back in, just to test that it still works. If it does work, logout and change session to openbox and login.
In "~/.config/ openbox/autostart.sh", enable the wicd-tray entry, by uncommenting it, and save the file. Logout and back in to test that it works... If that works, then logout again, and switch session to xfce4, and login.
Right-click your xfce4-desktop, choose Settings/Session And Startup/ Application Autostart.... Click add, give it a name like wicd-tray or something, and in the command-field put this without the quotes "wicd-gtk --tray". Click ok, and logout and back in, to see that it works.... It works perfect for me, and what could break it is if a update/upgrade some day will put a new wicd-tray-desktop in /etc/xdg/autostart, but in that case, it`s just to delete it again...
The last session I haven`t looked at. Actually, I have nerver logged into it. But I suppose you can manuallyt set if for that session too..