I've been running into this issue as well. A similar one is that the SSH connection is lost whenever the network is lost. I think both issues are supposed to be solved with the latest version of VB (4.3.8) from this ticket (https://github.com/mitchellh/vagrant/issues/2691).

I'd love to help out with doing some of your web stuff if you are interested. Shoot me an email, anhkiet(at)gmail