Today I decided to update my VirtualBox from 2.0.6 into 2.1.0, but I got a problem launching VirtualBox with normal user :
“Callee RC:Â NS_ERROR_FACTORY_NOT_REGISTERED (0x80040154)”
The problem occurred because the permission owner of folder /tmp/.vbox-vavai-ipc is owned by root and forbidden for another user. The solution is pretty simple. You must change the group owner of the folder (/tmp/.vbox-xxxx) or simply remove the folder so VirtualBox will be create another new with correct permission.