If you are running Ubuntu virtualbox guest then you cannot access the shared folder under /media/shared with regular user. However you can fix this by adding your user to vboxsf additional group.
Important! make sure you append the additional group so that other groups are not removed! Run te command below as exactly as seen and replace you username. If the permission is not applied immediately then reboot.
usermod -a -G vboxsf username
In case you forgot flag -a then it is bad but not hopeless Read the rest of this entry »