As I described here <http://forums.virtualbox.org/viewtopic.php?t=176&sid=5c3865b8fc040d1d33e43085ec81f1c2>
I tried to install ubuntu-7.04-desktop-i386.iso on a VirtualBox (1.38) machine
with WinXP as host machine (AMD Athlon Classic (SlotA) 900MHz, 768-SDRAM).
The install cd starts and I select "install". Then the ubuntu logo with
the orange progress bar is shown. After some seconds my own physical pc (not the virtualbox machine!) make a "reset".
There is no freez, no error message. It is just as I would press the
reset button on my physical machine.
I tried it in a fresh and new created machine. I attached the machine as a file here. The log can be found there two.
I tried it on another multi-boot machine with WinXP installed. There is the same behavior.
I have a problem with ReacOS (install-cd and live-cd), too. The virtual machine freeze while install but the physical host stays alive and make no problems.