As previously posted there is an ongoing issue with vboxnet0. It is the apparent cause of a system wide hard lock. I don’t think its a hardware issue, although it may end up being one. I hope not, therefore I will be investigating all possible software causes. Given the complexity of my system if can be many many things. It could be the bios, and general motherboard instability; and virtualbox has reported stability issues. It could be compiz, or the the binary nvidia drivers. I will know more soon.