I've been using VirtualBox for quite some time now. It has been a great tool to isolate my normal working environment from any changes I may make to the OS. It also allows me to work in my preferred OS - linux; even when I'm at work and am forced to use Windows. The road over the last year has been fairly easy. I've installed VirtualBox on a number of workstations and I even have one setup so that if the Windows box restarts, then one of the VirtualBox images automatically starts up (if I can remember how I did that I will updated this post).
Yeah, that's the error message I got one day when I was trying to upgrade the version of VirtualBox. To this day, I don't know what caused it. I suspect that there was some update to the server done by the server operations people that had some adverse affect on VirtualBox. Don't get me wrong - I don't think that the ops people messed anything up, I just think that what they pushed had some unintended consequence