I clean-installed Ubuntu 11.10 today, and then installed VirtualBox. This required me to add myself to the vboxusers group, and since 11.10 seems to no longer have a graphical app to add users to a group, I ran the following command:
sudo usermod -G vboxusers stephane
This is a problem. I now see what I should have run instead is:
sudo usermod -aG vboxusers stephane
The end result is I'm no longer in the groups I should be in. Including whatever group is required to run "sudo". When I run any command as sudo now, I get the following:
$ sudo ls [sudo] password for stephane: stephane is not in the sudoers file. This incident will be reported.
Is there a way to fix this, or do I need to re-install from scratch again?