ShellScript to workaround the problem that happens with VirtualBox on Mac OS X 10.9 called Mavericks. Run this after you close your VM.

wa_vb_osx_mav.sh

#!/bin/bash

unload() {
	sudo killall VBoxNetDHCP
	sudo /Library/Application\ Support/VirtualBox/LaunchDaemons/VirtualBoxStartup.sh stop
}

load() {
	sudo /Library/Application\ Support/VirtualBox/LaunchDaemons/VirtualBoxStartup.sh start
}

case "$1" in
  unload|remove)
    unload
    ;;
  load)
    load
    ;;
  *|reload)
    unload
    load
    ;;
esac