It may happen that, if you download a Slackware Current iso (which is a non ufficial iso), the boot is set in single user mode..
I downloaded the iso located here:
ftp://ftp.slackware.no/pub/[..]/slackware-current-15_May_2007-DVD.iso
The boot showed this annoying message:

Going to single user mode..

The network was down, too.. quite everything was down..

I looked in so many places.. I checked the permissions of every /etc/rc.d/* file, I obviously looked in my /etc/inittab, which reported "init 3" as default..

"So where is that f***ed init 1 set up!?!!?!"

The answer came when I compiled my kernel sources.. I needed to alter my lilo config file, /etc/lilo.conf, and I noticed that stupid line:


append="1"


Which makes the system boot in single user mode..

-.-

If you download a non ufficial iso set, make sure that lilo.conf does NOT contain that line!