[LightDM] lightdm fails to stop & can't change login

[Grant]

I've been using lightdm for about a year now and with all the versions
I've tried, Gentoo prints a message about lightdm and xdm failing to
stop if I reboot from the lightdm menu or the xfce4 menu.  If I issue
'reboot' as root from an xterm within xfce4, lightdm stops fine.  I
couldn't find anything in the logs, but in which one of syslog-ng's
logs should I look?

I'm also wonder if there's a way to switch login usernames when I'm
being prompted for a password by lightdm in case I mistyped the
username?

- Grant