Not sure if this applies still.. but from slackware12 up, I just do a few post install steps:
#Addusr
#touch /var/lib/slocate/slocate.db
#updatedb
#chmod +x /etc/rc.d/rc.messagebus
#/etc/rc.d/rc.messagebus restart
#chmod +x /etc/rc.d/rc.hald
#/etc/rc.d/rc.hald start or restart
last time I did start I got a message i didn't understand
so I did restart in Current upgrade and that worked fine.
#alsaconf
setup mixer
#alsamixer
make sure its unmuted - m key toggles mute
#alsactl store
Sometimes even though alsaconf may complain it can't find your module - once in Xfce you can configure your sound just goto the mixer and pick your snd module. Don't know it - in terminal #lsmod, or #lspci
Also goto /usr/share/sounds
Open folder
right click any sound file set properties to open with - i like Audacious its just simpler for me - close then click on the sound files to test your audio.
#chmod +x /etc/rc.d/rc.cups
#/etc/rc.d/rc.cups restart
Assuming you initially set it to start at but time.
#exit
Login as user
I always run $xwmconf to choose my desktop just to make sure my user account is associated properly with my desktop.
$startx and begin configuring the fun way
Rarely have install issues.