But I found a problem not related to Slackware, there is a problem with the kernel series 2.6.33.x and Nvidia legacy drivers. In short, once the driver is installed, the 'logout' action freezes the system and the only way to restore it is restarting manually, tough.
The solution, edit file '/etc/kde/kdm/kdmrc' and set:
# by default is false #TerminateServer=true TerminateServer=true
Solution source: black-screen-after-logout-in-slackware