I just upgraded to 13.10 and tried configuring at the Settings Manager, but it doesn't seem to work. So I tried configuring xfce4-power-manager/lid-action-on-ac and it didn't work eiter. Then, at last, tried editing /etc/systemd/logind.conf to:
#HandlePowerKey=ignore #HandleSuspendKey=ignore #HandleHibernateKey=ignore #HandleLidSwitch=ignore
#LidSwitchIgnoreInhibited is marked "yes" by default, but I've tried switching it to "no", with no response.
So, the computer is still suspending when the lid is closed... What else should I try? Or is it Xubuntu 13.10 installation that is bugged?