lightdm doesn't load correctly on Ubuntu 12.10
Ubuntu 12.10 doesn't load correctly because lightdm shows only a mouse pointer and a blinking command-line cursor.
I don't know if this is only Ubuntu 12.10 specific bug, because a similar error appeared on my friend's computer back in 2011 on Ubuntu 11.10. However, switching to a command line and restarting lightdm solves the problem per instance. Also rebooting the device solves it, but also only for the specific boot. Another reboot ends with the same "black screen with a working mouse pointer and a blinking cursor".
I am using Asus Zenbook ux32vd (Intel HD Graphics 4000 + not used Nvidia GT620M - Optimus technology).