I installed Kali Linux on VirtualBox. Worked like a charm, logged in, installed some software with sudo..using my password. Then I left the computer for an hour, and when I got back I had to log back in..and my password didn't work. There is only root user on the installation, and I know the password is correct because I used it as sudo. Anyone else had this problem, or know what might'v caused it? I'm considering installing Kali instead of Ubuntu on this laptop, but not if it's gonna lock me out