VirtualBox: I cloned Ubuntu...so why are some files different?

view story

http://askubuntu.com – I am using VirtualBox 4.2 with Ubuntu 12.10 (installed from the minimal CD). I want to clone the Ubuntu guest on my Windows host and run it on my Mac host. However, when I did this, I noticed at least one important file was changed. On Windows/Ubuntu, I configured /etc/init/tty1.conf for auto-login. However, when I run the cloned VDI on Mac/Ubuntu, this file has different contents. As a result, the behavior is different when I boot the Ubuntu VM on the Mac machine. Any idea what types of things change when running a VDI file on different host OS's? I already know that the network settin (HowTos)