Earlier this week, I upgraded VirtualBox from 4.0.12 to 4.1.0, being excited to read in the changelog that it finally supports Direct3D in Windows guests (I was hoping to see my Windows Experience Index to become higher than 1.0). Unfortunately, not only VirtualBox now crashes when asking Windows 7 to calculate the Windows Experience Index, but my PC is no longer able to shutdown. It freezes very close to shutdown, after the "halt" command is called for all processes. What I get is a kernel panic, as you can see in this screenshot.
The keyboard is totally unresponsive, and you have to reboot the PC by pressing the reboot button. When I do that, the PC first seems to reboot correctly, but suddenly decides to reboot again a few tens of seconds later, sometimes even after I’m already logged in. After the second reboot, everything goes fine again… till I try to shutdown my PC again. Hum! So I uninstalled VirtualBox 4.1.0, as this version seems broken, as reported in the VirtualBox bugtracker too.
These days, I’m pretty irritated with all these new releases which break stuff. Mageia 1 and KDE 4.6 (also here and here) come to mind. Instead of new releases with new features, I would prefer stable releases with bugfixes only.
Update: VirtualBox 4.1.2 has this problem fixed.