Linux – Timeout while waiting for the machine to boot!! Vagrant-Virtualbox

I have gentoo(linux) host machine. On which, I have Virtualbox 4.3.28 and vagrant 1.4.3 installed(these are the latest available version for gentoo).

On vagrant up, the Ubuntu 14.04 gets launched. I'm also able to ssh to Ubuntu. I also tried vagrant destroy and then vagrant up. But then as soon as it gets launched I get the following error. Below is my Vagrantfile and output error.

P.S. I have created Ubuntu 14.04 base box from scratch.

Vagrantfile

# -*- mode: ruby -*-

# vi: set ft=ruby :

    Vagrant.configure(2) do |config|
      config.vm.box = "Ubuntu"
      config.vm.boot_timeout = "700"
      config.vm.provider :virtualbox do |vb|
      vb.gui = true
      end

    end 

Output in terminal

Bringing machine 'default' up with 'virtualbox' provider...
[default] Clearing any previously set forwarded ports...
[default] Clearing any previously set network interfaces...
[default] Preparing network interfaces based on configuration...
[default] Forwarding ports...
[default] -- 22 => 2222 (adapter 1)
[default] Booting VM...
[default] Waiting for machine to boot. This may take a few minutes...

Timed out while waiting for the machine to boot. This means that
Vagrant was unable to communicate with the guest machine within
the configured ("config.vm.boot_timeout" value) time period. This can
mean a number of things.

If you're using a custom box, make sure that networking is properly
working and you're able to connect to the machine. It is a common
problem that networking isn't setup properly in these boxes.
Verify that authentication configurations are also setup properly,
as well.

If the box appears to be booting properly, you may want to increase
the timeout ("config.vm.boot_timeout") value.

Any solution to fix this problem?