I just got Slackware 13.37 up and running and all is well except for the KDE Desktop Effects. If I log in as root, they're enabled and work fine. However, when I log in as a user they are disabled and the option to enable them is greyed out.
Other OpenGL programs run fine as a user, such as the glxgears test program and OpenGL screensavers.
ATI card running this driver:
It must be some kind of permission issue but I'm not really sure where to look.