Зависает сборщик виртуальной коробки windows 7 ISO

Когда я собираю коробку win 7 с использованием упаковщика, она зависает в ожидании доступности SSH:

==> virtualbox-iso: Downloading or copying Guest additions
    virtualbox-iso: Downloading or copying: file:///vb/VBoxGuestAdditions.iso
==> virtualbox-iso: Downloading or copying ISO
    virtualbox-iso: Downloading or copying: file:///home/foo/win7_prof.iso
==> virtualbox-iso: Creating floppy disk...
    virtualbox-iso: Copying: ./answer_files/7/Autounattend.xml
    virtualbox-iso: Copying: ./scripts/dis-updates.ps1
    virtualbox-iso: Copying: ./scripts/microsoft-updates.bat
    virtualbox-iso: Copying: ./scripts/win-updates.ps1
    virtualbox-iso: Copying: ./scripts/openssh.ps1
    virtualbox-iso: Copying: ./scripts/oracle-cert.cer
==> virtualbox-iso: Creating virtual machine...
==> virtualbox-iso: Creating hard drive...
==> virtualbox-iso: Attaching floppy disk...
==> virtualbox-iso: Creating forwarded port mapping for SSH (host port 3143)
==> virtualbox-iso: Executing custom VBoxManage commands...
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1420575242 --memory 2048
    virtualbox-iso: Executing: modifyvm packer-virtualbox-iso-1420575242 --cpus 2
==> virtualbox-iso: Starting the virtual machine...
==> virtualbox-iso: Waiting 2m0s for boot...
==> virtualbox-iso: Typing the boot command...
==> virtualbox-iso: Waiting for SSH to become available...

Есть опыт решения этой проблемы?