I’m going on a CEH (Certified Ethical Hacker) course in a couple of month and to prepare for that course try to play with the Linux distribution Kali.
I found this fine guide http://kanishkashowto.wordpress.com/2013/09/03/how-to-install-kali-linux-in-virtualbox-step-by-step-guide/, but the installation failed all the time at 69% finished. And looking at the comments in the guide, I could see that other users had the same problem.
I then started Kali as a Live distribution. That works, so I tried to install it while running the Live session. And that worked. Now Kali got installed :-).