Vagrant reporting VirtualBox guest additions out of date

Fairly new to Vagrant, so bear with me if I don't understand the process.

I downloaded a CentOS box off http://www.vagrantbox.es/

Started it up running VirtualBox 4.2.4 and got this message:

[default] The guest additions on this VM do not match the install version of
VirtualBox! This may cause things such as forwarded ports, shared
folders, and more to not work properly. If any of those things fail on
this machine, please update the guest additions and repackage the
box.

Guest Additions Version: 4.0.8

VirtualBox Version: 4.2.4

So I used the vbguest plugin to update the guest additions, then repackaged the box as suggested. Having replaced the old box and loading it up I get the same message about guest additions being outdated, but vbguest reports that they are up to date (the automatic vbguest update is disabled in my Vagrantfile):

Vagrant::Config.run do |config|    
    config.vm.box = "centos56_64"

    config.vbguest.auto_update = false
    config.vbguest.no_remote = true
end

And the commands:

dtest$ vagrant up
[default] Importing base box 'centos56_64'...
[default] The guest additions on this VM do not match the install version of
VirtualBox! This may cause things such as forwarded ports, shared
folders, and more to not work properly. If any of those things fail on
this machine, please update the guest additions and repackage the
box.

Guest Additions Version: 4.0.8
VirtualBox Version: 4.2.4
[default] Matching MAC address for NAT networking...
[default] Clearing any previously set forwarded ports...
[default] Forwarding ports...
[default] -- 22 => 2222 (adapter 1)
[default] Creating shared folders metadata...
[default] Clearing any previously set network interfaces...
[default] Booting VM...
[default] Waiting for VM to boot. This can take a few minutes.
[default] VM booted and ready for use!
[default] Mounting shared folders...
[default] -- v-root: /vagrant

dtest$ vagrant vbguest --no-install
[default] Detected Virtualbox Guest Additions 4.2.4 --- OK.
[default] Virtualbox Guest Additions on host: 4.2.4 - guest's version is 4.2.4

Since they appear to be updated after an install, I could ignore the message. But is it possible to get rid of it?