Created attachment 104559 [details]
Glxinfo

My current setup is: SLiM as login manager, Openbox as window manager, feh to
show the desktop wallpaper, Xcompmgr for transparency, xfce4-panel for the
panel.
My autostart for Openbox is like this:
feh --bg-scale /home/davide/Immagini/background.jpg &

if which xfce4-panel >/dev/null 2>&1; then
  (sleep 2 && xcompmgr) &
  (sleep 2 && xfce4-panel) &
fi

I'm using linux 3.15.8, Mesa 10.2.5 and Xorg 1.16 on archlinux.