did you try to reboot? i've installed it yesterday and it makes me the same issue.
after a poweroff (dinner pause :-) ) it let me in as root

ernia, pure genius! Rebooting did it, at least for cups & open office. That's what I get for not taking a lunch break. Thanks, john

@wetterau
I suggest you reference Documentation before the forum.
http://doc.slitaz.org/en:start
Pick your language,go to Guides
This information is from:
http://doc.slitaz.org/en:guides:printer

Printing
Installing a Network Printer

Do as root in xterm:
# tazpkg get-install cups
# addgroup tux lp

Change some lines in /etc/cupsd.conf (# leafpad /etc/cupsd.conf):
# Administrator user group...
SystemGroup lp

# Restrict access to the admin pages...

Order allow,deny
Allow 127.0.0.1


# Restrict access to configuration files...

AuthType Default
Require user @SYSTEM
Order allow,deny
Deny From None
Allow From 127.0.0.1

Set the admin password for cups:
# lppasswd -g lp -a tux

Now you should be able to have access to administration in cups with your browser with http://localhost:631/

Go to:
http://doc.slitaz.org/en:guides:printer
to see the rest of the tutorial.

Thanks, mojo. I did all that, but apparently I needed to reboot before it would work. john

@mojo
the steps that you report are required to admin cup as tux user or lp group, but you should be able by default to login and do administration tasks as root. i have not been able until i have rebooted, and i'm not so glad to receive too much RTFM . It think that you can't expect that every new user has already read every page and every row in the docs ;-)
@wetterau
me and you must be two jackass :-)
i bet that you, like me, have started the daemon in the very same moment you installed cups. here's the result:

root@sl3:/home/fabio# ps aux | grep cups
 1779 root     /usr/sbin/cupsd -C /etc/cups/cupsd.conf 
 1976 root     /usr/sbin/cupsd -C /etc/cups/cupsd.conf 
root@sl3:/home/fabio# 

the /post_install() script of the package launches the daemon itself and /etc/init.d/cupsd script does not check if cups is already running (e.g. if /var/run/cups/cups.sock is there or not) so it launches another session of cups and as a result you can't login ...
so, in your pc that now let you login in cups close the browser, run

/etc/init.d/cupsd start

and try to login again. if you can't login put solved in the topic title,put the solution (or the error to avoid :-) ) in the first post, and i will fill a bug (or a dumbproof feature request) in slitaz labs
Now that you can handle the forum make more readable the post about getopenoffice, i would delete the new one and put solved in the original topic title :-)

this /etc/init.d/cupsd does not let you start two istances of cups:

#!/bin/sh
# /etc/init.d/cups: Start, stop and restart Cups deamon on SliTaz, at boot
# time or with the command line.
#
# To start daemon at boot time, just put the right name in the $RUN_DAEMONS
# variable of /etc/rcS.conf and configure options with /etc/daemons.conf.
#
. /etc/init.d/rc.functions
. /etc/daemons.conf

NAME=Cupsd
DESC="cups deamon"
DAEMON=/usr/sbin/cupsd
OPTIONS=$CUPSD_OPTIONS
PIDFILE=/var/run/cups/cups.sock

case "$1" in
	stop)
		echo -n "Stopping $DESC: $NAME... "
		killall -q cupsd
		rm -f $PIDFILE
		status
		;;
	start)
		if [ ! -e $PIDFILE ] ; then
			echo -n "Starting $DESC: $NAME... "
			$DAEMON $OPTIONS
			status
		else
			echo -n "Not starting $DESC: $DESC is already running"
			false
			status
		fi
		;;
	*)
		echo ""
		echo -e "\033[1mUsage:\033[0m /etc/init.d/`basename $0` [start|stop]"
		echo ""
		exit 1
		;;
esac

exit 0

i've submitted it in slitaz labs, if you trust me you can download it from here:
http://labs.slitaz.org/attachments/176/cupsd

Yesterday I managed to configure my HP 6500 Officejet as a network printer using the cups admin web page (after downloading and unpacking the hplip source (3.11.1) to get the right ppd file).
Today when I started up and logged in, the webpage (localhost:631) wasn't available. When I grepped for cupsd in the output of ps, it wasn't there.
Is the cups installer supposed to modify rcS.conf to put it into the DAEMONS section? Are you supposed to always run the cups daemon manually?
I faithfully followed the installation docs to do everything right (they're now a little out of date for slitaz 3.0 as the cups configuration has changed), but I'm not sure about the daemon thing. Did I miss a step?
I made the mod to rcS.conf and rebooted. Now I can print again!

Thanks for an awesome distro that runs like a charm on my ancient Emachines M5305 laptop.

The cups post_install script starts cupsd once when it's installed and stops it if it's running in pre_remove.
The user has to add cups to RUN_DAEMONS of /etc/rcS.conf so it will autostart on every boot.
Not what I'd call user friendly.

The post_install script could be made to add cupsd to RUN_DAEMONS... but I'm not sure people would want that :/