If you're using Vagrant with VirtualBox you will find that in your shared /vagrant
folder that any chown/chmod changes you run won't have any affect. This is a bit weird but you can work around it in your Vagrantfile by adding the following line:
config.vm.synced_folder ".", "/vagrant", :extra => "dmode=755,fmode=755
Depending on your needs you may have to change the octal values.
since Vagrant 1.3.0